Bergmann MP 18,I machine pistol

The Bergmann MP 18,I (Maschinenpistole 1918 I) is the machine pistol or submachine gun that is often credited as the very first. This gun was designed by German arms designer Hugo Schmeisser (1884 - 1953) and manufactured at the Theodor Bergmann Waffenbau Abteilung ('Theodor Bergmann Weapons Fabrication Department') in Suhl, Thuringia. It represented a major landmark in the development of the submachine gun as this class of weapon is understood today, and created an accepted standard after which many subsequent submachine gun designs would be modeled. In spite of this, little research of depth has been undertaken into the development and history of the MP 18,I. This page details the creation, adoption, and service use of the MP 18,I during the First World War and the subsequent interwar period.

The most important precursory invention in the development of the MP 18,I machine pistol was the lange Pistole 08 ('long Pistol'), commonly known today as the 'Artillery Luger'. This weapon was a modification of the standard German service Luger P.08 self-loading pistol, albeit built with a 200 mm (7.8 in) long barrel which was double the length of the standard P.08 barrel, and issued with a detachable wooden shoulder stock. The lange Pistole, or lP.08, was introduced into German military service in June 1913, though it was not originally conceived with the role of an assault weapon, instead being issued as a backup arm for artillerymen to free up rifles and carbines for the infantry. However, by 1916, an increased demand for pistols among the infantry resulted in the Preußische Kriegsministerium (Prussian War Ministry) considering the wider distribution of pistol-calibre arms across all services.

Because its increased barrel length permitted relatively accurate fire over short-range distances, the lange Pistole was considered most suitable for this role. Necessary modifications were made to the lP.08 in order to repurpose this design into a weapon suitable for infantry assault actions. Tests of the lP.08 coupled with a 32-round high capacity drum magazine, replacing the P.08's standard 8-round box magazine, were conducted in 1916, and the Preuß. KM recognised the potential benefits of the lP.08 over existing infantry rifles and carbines within the context of close-quarters trench combat, and the potential use of the weapon in conjunction with hand grenades due to its light weight.

The Preuß. KM approved increased orders for new lP.08 long pistols and on the 4th November 1916, Generalquartiermeister Erich Ludendorff ordered the allocation of ten lP.08 pistols to each Infanterie-, Jäger-, and Sturm-Kompagnie. These were to be distributed at the discretion of the company commander on a situational basis. Stosstruppen and Pionere formations were often given priority for these weapons, as they would be the most likely to engage in trench-clearing duties.

The adoption of the lP.08 was not, however, without a caveat. Owing to a severe shortage of regular pistols in circulation among the officer corps, the Oberste Heeresleitung (O.H.L.; 'Supreme Army Command') decreed on the 6th March 1917 that all frontline units were now subject to a strict limit on the number of pistols permitted per company: twelve in companies serving on the Western Front, and only six in companies serving on the Eastern Front. This decree noted that newly-issued lP.08 pistols were to be counted under this order, so any companies in the West which were fully equipped with ten lP.08s were only permitted two additional 'short' pistols - whereas companies in the East were expected to return all their 'short' pistols immediately! Thus even from the outset of its distribution, it became clear that the lP.08 alone could not entirely satisfy the high demand for automatic pistols among frontline infantry troops.

The pertinence of both the P.08 and lP.08 in assault actions was surmised in the memoirs of the Badisches Leib-Grenadier-Regiment Nr. 109 (28. Infanterie-Division):

"In the summer of 1916, each company was equipped with twelve Pistole 08 pistols (self-loading pistols with an eight-round magazine, 9mm caliber) instead of six. Unlike a rifle, the self-loading pistol did not require the shooter to manually cock and recock the bolt; these movements were performed automatically by the pressure of the propellant gases during firing, so that the pistol was reloaded immediately after each shot. A significant advance came in the autumn of 1917 with the introduction of the 32-round drum magazine, which increased the rate of fire from 40 to 110 rounds per minute. Each company received ten pistols with carrying equipment; similar trailing magazines were also supplied for the rifle, but were only used by individual sentries in quieter positions. [...] Pistols, along with hand grenades, were standard equipment for assault troops during patrol operations and when digging trenches."

Despite the adoption of the 32-round magazine for the lP.08 in late 1916, many German units did not receive these until late 1917 or even early 1918.

To the extent that the lP.08 can be considered a precursor of the machine pistol or submachine gun concept, the German Army became the first to issue such weapons with the intent of employing them specifically as assault weapons. The Italian Army had a similar weapon, the Pistola Mitragliatrice Fiat mod. 1915 (popularly known as the 'Villar Perosa'), a twin-barrelled machine gun chambered in the 9x19mm Glisenti pistol cartridge, which had been in service since September 1915. The Villar Perosa, however, had been primarily deployed in the role of a light support weapon fired from a fixed mount (initially a gun shield, later a bipod) and though its potential application as a dismounted assault weapon had been recognised by some Italian tacticians as early as October 1916, this would not be formulated into official doctrine until June 1917 with the raising of the Reparto d'Assalto ('Assault Departments').

The serious development of machine pistols proper began around this time, with Germany's ally Austria-Hungary making several concerted efforts to create a copy of the Villar Perosa, resulting in several prototype designs which were put to trial such as the Anschlagpistole M.12, Pistolen-M.G. M.17, and Sturmpistole M.18. The close co-operation and sharing of intelligence between Germany and Austria-Hungary makes it implausible that the Germans were not at least aware of the existence of the Villar Perosa, and since March 1917 the Austro-Hungarian infantry training school in Levico, overseen by German instructors, had made use of a captured Villar Perosa in Sturmtrupp courses. When the German Army committed six divisions to participate in the Caporetto Offensive (24th October - 19th November 1917) on the Italian Front, the Austro-Hungarians had begun to issue their Sturmpistole to select infantry divisions for field testing. The K.u.K. 50. Infanterie-Division, for instance, deployed the Sturmpistole in combat for the first time on the opening day of the offensive, when they captured the village of Gabrije to pave the way for the main assault against the Italian lines by the German 12. Infanterie-Division.

German troops further came up against the Italian machine pistol, the Villar Perosa, during the abortive offensive at the First Battle of Monte Grappa (13th - 26th November 1917). In the aftermath of the German intervention on the Italian Front, an estimated 2,000 Villar Perosa machine pistols had been captured by the Austro-Hungarian and German forces. A great deal of these were pressed into Austro-Hungarian service, though at least some appear to have been taken into German use by the Flieger-Abteilung (A) 219 to be fitted on reconnaissance planes using proprietary improvised mounting systems.

Immediately after the Caporetto Offensive, the German and Austro-Hungarian war ministries began collaborating on the development of a machine pistol for service in both armies (see: Trial and Adoption). It was in this context that the first record of the Maschinenpistole MP 18,I appeared in the final month of 1917.

Left: Three infantry-pattern Villar Perosa machine pistols, likely captured at Caporetto in 1917, fitted to a German Halberstadt CL.II aircraft using improvised mounts. Right: Austro-Hungarian
Sturmtruppen training with a captured Villar Perosa at Levico in March 1917. The Central Powers were first exposed to the concept of the machine pistol through samples of this weapon
obtained from the Italian Front.
(Image 2: Österreichische Nationalbibliothek)

Design aspects of the MP 18,I and comparison to contemporary designs

The MP 18,I operates on a open-bolt straight blowback action in which the bolt is held in the open position when the weapon is cocked for firing, and comes forward when the trigger is pulled to collect a cartridge from the magazine, push the cartridge into the breech, and proceeds to close over the breech until the firing pin strikes the cartridge primer. The bolt is then blown back by the cartridge ignition until it travels to the rear of the receiver, upon which it returns forward toward the breech to repeat the cycle without interruption. This cycle repeats as long as the trigger is held. The spent cartridges are ejected via an open ejection port on the right side of the magazine housing, parallel with the magazine feed. The weapon utilises a cylindrical bolt housed inside a tubular receiver with a long cocking slot cut into the right side of the receiver through which the charging handle protrudes. The receiver is fitted to a short wooden stock; for quick disassembly, the receiver tips open on a forward hinge to allow the end cap to be removed, allowing open access to the bolt and mainspring via the rear end of the receiver. The receiver locks in place onto the stock via a catch on the end cap.

The bolt used in the MP 18,I is a wide diameter design comprising three parts: the main bolt body; the firing pin; and the extractor. The bolt body contains the main mass and forms the forward section of the bolt, and also carries the charging handle. The front part of the firing pin sits inside the length of the bolt body, while the wider back end of the firing pin forms the rear section of the bolt and rides on a long cylindrical guide rod with a thin buffer spring coiled around it. A small opening is cut into the bolt face through which the firing pin protrudes, and the extractor sits over the bolt face opening. Despite the bolt body and firing pin being separate components, the firing pin does not move independently of the bolt body and is fixed in place, only moving with the rest of the bolt. The claw-type extractor hooks against the rim of the cartridge when the bolt closes fully over the breech, and then carries the spent cartridge with the bolt until it reaches the ejection port.

The bolt sear of the MP 18,I is far forward of the trigger, and instead of actuating the sear directly, the trigger pushes against a spring-loaded cylindrical rod which extends across the length of the trigger housing and causes the sear to drop, releasing the bolt. The MP 18,I trigger mechanism has no fire selector and cannot be set to fire single shots.

The MP 18,I has no mechanical trigger lock or forward safety to lock the bolt in the closed position. The only safety provision is a bolt hold catch cut into the rear part of the cocking slot. The bolt can be held fully to the rear, in the open position, by latching the bolt handle into this hold catch, preventing it from coming forward. Two downsides are evident to this system: firstly, that keeping the bolt in the open position invites the entry of dirt into the receiver; and secondly, there is a hazard of accidental discharge if the bolt handle is knocked out of the hold catch. Similarly there is a risk of accidental discharge when the bolt is left in the closed position, as knocking the weapon with enough force to cause the bolt to move can also result in accidental discharge. This problem was eventually addressed in later improvements to the MP 18,I in the 1930s (see The 'MP 18,Iv' System Schmeisser).

The magazine used in the MP 18,I is a 32-round drum magazine known as the TM.08 Trommelmagazin (often abbreviated as 'Tr. magazin'). This is the same type of drum magazine issued with the aforementioned lP.08 long pistol. The magazine uses a single-stack load with a single-position feed opening, and due to its unconventional design it requires the use of a special loading tool in order to fill to capacity. Because this magazine is originally designed to feed through the Luger P.08 pistol grip, the feed neck of the magazine is built at a 45° canted angle and thus the magazine housing of the MP 18,I is canted at the same angle. Since the MP 18,I magazine housing is significantly shorter than the P.08 pistol grip, use of the TM.08 magazine in the MP 18,I requires the feed neck of the magazine to be fitted with a special collar in order to accommodate the different housing dimensions and to prevent it from overfeeding into the MP 18,I receiver. The magazine release catch is a small push-in button located on the top of the magazine housing.

In comparison to the Villar Perosa, the only other machine pistol of contemporary note, the MP 18,I is a decidedly basic design. Both weapons are essentially similar mechanically as they both operate on a blockback action with a cylindrical bolt housed inside a tubular receiver, however the main aspect in which the Villar Perosa differs from the MP 18,I in that it employs a locking mechanism in which the bolt engages against angled cam slot behind the breech, which prevents the firing pin from coming forward until the bolt has fully cammed and sealed against the breech. This was intended to prevent out-of-battery discharge. In the opinion of contemporary German small arms expert Max Schwarte, writing immediately after the war in Die Technik im Weltkriege (1920), the Villar Perosa locking mechanism did not work reliably, which may explain why no such system was imitated in the MP 18,I. The bolt of the MP 18,I is also larger and heavier than that of the Villar Perosa, resulting in a great difference in the cyclic fire rate between the two weapons; the MP 18,I fires at around 500 rounds per minute, compared to the Villar Perosa's approximate 1,200 rpm per barrel.

Except for the use of an overhead box magazine and folding bayonet, the Moschetto Automatico Revelli-Beretta, taken into service toward the end of the war by the Italian Army, is very similar in layout and handling to the MP 18,I. Both weapons are furnished with short wooden buttstocks, with tubular receivers and charging handles situated on the right. The principle difference between the MP 18,I and the Revelli-Beretta is in the trigger mechanism; the Revelli-Beretta's trigger acts on a trip mechanism in which the sear resets after the trigger is fully repressed, allowing for single shots only, making the Italian weapon more comparable to the lP.08 long pistol in terms of performance.

The design process under which the MP 18,I was developed remains largely unknown, owing to the lack of available documentation. A commonly repeated narrative is that the MP 18,I was made in response to a request from the Preußisches Gewehr-Prüfungskommission (Prussian Rifle Testing Commission) for a portable machine gun in a pistol calibre, dating back to 1915. A requirement for a weapon of this type was supposedly decided after the Commission observed the test of a Luger P.08 pistol converted into a machine pistol and fitted with a rifle stock, submitted by Georg Luger himself. A typical claim tying into this narrative is that the Theodor Bergmann Waffenbau Abteilung commenced work on the MP 18,I machine pistol by 1916, under the name 'Bergmann Muskete'.

In fact there is record of a 'Maschinenpistole Luger' submitted to the Preuß-Kriegsministerium, though this trialled in December 1917 as an aerial arm fitted to the mounting of an MG 14 Parabellum machine gun. Much like the lP.08, this gun fed from a 32-round drum magazine, and a detachable buttstock was offered as an option for this weapon for the possibility of off-hand use, but there was no interest from the Preuß. KM in adopting Luger's design. Another machine pistol conversion of the Luger P.08, designed by Heinrich Senn of the Waffenfabrik Bern in Switzerland, was also submitted to the Preuß. KM in 1915 and was tested by the Luftstreitkräfte in 1917 as a potential armament for aerial observation crew. This model is described in surviving documentation in similar terms, with a shoulder stock, bipod, extended box magazine of 25 rounds, and barrel jacket. Though these P.08 conversions were undoubtedly similar in principle to the MP 18,I machine pistol, there is - to the author's knowledge - no documentary evidence that either the Luger or Senn designs created any serious demand from the Preuß. KM for a machine pistol as early as 1915 or 1916.

The earliest known record of the MP 18,I first appears in the German patent № 319,035, applied for by Theodor Bergmann on the 30th of December 1917. This protected the mainspring and buffer design for the MP 18,I bolt, and also illustrates that several design aspects such as the canted magazine feed for the TM.08 Trommelmagazin were already present at this stage. A second patent was applied for by Theodor Bergmann on the 26th of April 1918, protecting the tipping receiver assembly and rear end cap lock. These patent application dates do not necessarily indicate when exactly the gun was actually designed - no doubt work had been actively undertaken for at least a few months prior - but it does give a rough idea of the timeframe under which the MP 18,I was completed, in absence of any other reliable primary sources. The period of late 1917 is consistent with the development of the MP Schwarzlose (see Trials and Adoption), a competitor to Bergmann's design; Schwarzlose reported that design work on their gun had finished in November 1917. In light of this, it does not seem likely that any active work on the MP 18,I was being carried out as early as 1915. Furthermore, any record of a 'Bergmann Muskete' during the wartime period probably refers not to the MP 18,I but to the lMG 15 n/A light machine gun. In contemporary German military parlance, 'muskete' was a term used to refer primarily to light machine guns (i.e. the Madsen, Chauchat, and Lewis guns), not machine pistols, which were known as 'maschinenpistolen', and within the German Army there was some significant overlap in the doctrinal roles of the lMG 15 n/A and the Madsen 'Muskete'.

The earliest physical prototype of the MP 18,I that still exists today is in the collection of the Vojenský historický ústav (VHU) in Prague. This gun is serial № 2 - presumably the second MP 18,I ever made - and even in this very early sample it can be seen that most aspects of the design had effectively been finalized already. The only significant difference between this prototype and the final production models that followed is the presence of a twin trigger group, which gives uninterrupted automatic fire from the front trigger and single shots from the rear trigger. This is comparable to the trigger layouts of the Italian OVP and MIDA-Savoia submachine guns which appeared during the same period, though it seems improbable that there could have been any influence from the contemporaneous Italian weapons which had not yet appeared on the battlefields. The name 'M.P. 18,I.' already appears on the top of the magazine housing, indicating not only that this designation had already been bestowed upon the weapon at the factory prior to its adoption by the German Army, but also that the first prototypes could not reasonably have been built any earlier than the final months of 1917, as Theodor Bergmann could not possibly have predicted in 1916 that his machine pistol would not be taken into service for another two years - let alone that the war would even drag on for that long.

Another early pre-production weapon, serial № 21, exists in the UK. This is identical to the final production pattern, employing a single trigger mechanism, but shares the same style of hand-etched identifying markings on the magazine housing as VHU's serial № 2. In these prototypes, the designation is engraved in a quite elaborate font (probably hand-etched), with the serial number at the top and the proofing stamp below. The style of markings present on these early examples of the MP 18,I closely aligns with those seen on late production examples of the lMG 15 n/A light machine gun made in 1918, which would likely place them in a similar timeframe.

In the typical mass-produced examples of the gun, the magazine housing bears markings in a simplified font, with the serial number placed below the proofing stamp. Additionally, all known guns from № 21 onward bear the factory stamp 'Theodor Bergmann Abteilung Waffenbau' on the left side of the receiver casing, a marking which is absent from serial № 2.

Owing to the lack of available records, the exact circumstances and timeframe under which the MP 18,I was trialled by the Preuß. KM and placed into service remain unclear. However it is known that development of a rival machine pistol design was occurring concurrently at the Andreas Schwarzlose Gesellschaft für Waffenerzeugnisse in Berlin. The Maschinenpistole Schwarzlose, which had been in active development since at least November 1917, was envisaged as a joint Austro-German project, with close collaboration between the Preuß. KM in Germany and its Austro-Hungarian counterpart, the K.u.K. Kriegsministerium, and it was hoped that the weapon would be taken into service in both countries.

It is clear, however, from the records of the K.u.K. KM that the MP Schwarzlose project was met with problems from an early stage. In late 1917 the Austro-Hungarians had ordered a small batch of 100 samples for trial and study, but by February 1918 only a single gun had been sent to the K.u.K. KM as Schwarzlose repeatedly struggled to deliver on small orders. By March, both the German and Austro-Hungarian armies had effectively abandoned the MP Schwarzlose and decided to press ahead with the adoption of rival designs which were more readily available: the Austro-Hungarians with the Sturmpistole M.18, a copy of the Villar Perosa; and the Germans with the MP Bergmann, or MP 18,I. There is some indication that these choices were made somewhat reluctantly, and that both armies had, in fact, thought very highly of the MP Schwarzlose; Generalmajor Ernst von Wrisberg, director of the Preuß. KM's Allgemeinen Kriegs-Departements ('General War Department'), wrote in 1922 that adoption of the MP 18,I was only approved "after the completion of an excellent Maschinenpistole Schwarzlose, suitable for mass production, had not been finished in time". Owing to Schwarzlose's inability to meet the production demands necessary for even a small batch of prototype guns, it is unlikely that thorough comparative trials between the MP Schwarzlose and MP 18,I were ever actually undertaken, and thus the decision to take the MP 18,I into service seems to have been made out of necessity rather than as a result of exhaustive evaluation.

The Maschinenpistole Schwarzlose, an abortive design made in early 1918 as a competitor to the Bergmann MP 18,I.
(Tula State University)

This decision had evidently been made by the 18th of March 1918, when Generalquartiermeister Erich Ludendorff distributed a table of ordnance projections for the year 1918, which included an order for 50,000 'Maschinenpistole Berger' (presumably an abbreviation of 'Bergmann'). Unlike other small arms ordnance listed in this table such as rifles and machine guns, Ludendorff was unable to give monthly projections for machine pistol production, only a yearly total, as large-scale manufacture of the MP 18,I had not yet commenced by this stage, though a rough monthly average can be discerned from later production figures (see Production and acceptance numbers). Official manuals for the weapon, entitled Leitfaden für die Maschinenpistole 18,I ('Guide to the Machine Pistol 18,I'), were published by the Reichsdruckserei in Berlin the following month. Production of the MP 18,I to meet this military contract presumably commenced at the Bergmann Waffenbau Abteilung around April - May 1918.

Additional note should be made of several other machine pistol designs which appeared in Germany during 1918, including a model by Fritz Walther, which was made in at least two different prototype models. The timeframe of this gun's development is uncertain; the first patent protecting its operational mechanism was applied for on the 25th of May 1918, two months after the MP 18,I had already been adopted. Wrisberg makes no mention of this Walther design in his memoir which may indicate that it either was not completed in time for trial in early 1918, or that it simply failed to make any considerable impression on the Preuß. KM. Another design known as the Maschinenpistole Hoffmann appeared on paper but there is no known evidence that it was ever built in physical form.

The MP 18,I and the Spring Offensive of 1918

A common and persistent claim in popular histories of the First World War is that the MP 18,I machine pistol was employed by German Sturmtruppen during the Spring Offensive (21st March - 18th July 1918), with some sources partially attributing the German success in the early stages of the offensive to the use of these guns. These claims are inaccurate, as the MP 18,I had not even been placed into active service by the time that the offensive was launched. No such guns were used by German troops in the spring of 1918 and therefore the initial successes of the operation certainly had nothing to do with the use of machine pistols.

Troop trials of the MP 18,I machine pistol were organised by the Preuß-Kriegsministerium in July 1918, with the 237. Infanterie-Brigade (119. Infanterie-Division) being selected to receive the first batch of 216 guns for the purpose of evaluating their performance under the conditions of the Western Front. These were distributed to Infanterie-Regiment Nr. 46 (1. Niederschlesisches), Reserve-Infanterie-Regiment Nr. 46, and Infanterie-Regiment Nr. 58 (3. Posensches). A primary concern of the trials was to determine the efficacy of the machine pistol in comparison to the existing MG 08/15 and lMG 08/18 light machine guns as weapons for 'assault defense' (Sturmabwehr, literally 'Storm defense'), which were themselves recent additions to the German Army's infantry arsenal. The emphasis placed on this aspect in particular was perhaps a recognition that by the Kriegsministerium that, following the abandonment of Operation Michael on the 5th April 1918, the primary use of the machine pistol was going to be as a weapon of defense and counterattack against Allied assaults on German positions.

In order to dictate the rate of distribution for this new type of weapon, the Kriegsministerium ordered the creation of the Maschinenpistole-Trupp (or M.P.-Trupp) within the 237. Infanterie-Brigade, a small squad-sized unit which would be armed with MP 18,I machine pistols. In the initial outline of the M.P.-Trupp conceived in June, the unit was sized at 14 men, comprising 6 gunners, 6 ammunition carriers, an officer, and an armourer. It was officially recommended that the guns would be assigned to non-commissioned officers of Gefreiter, Feldwebel, or Unteroffizier rank, whilst ammunition would be distributed to enlisted men. One ammunition carrier was assigned to each gunner, and was issued with an lP.08 long pistol, certainly to maintain logistical compatibility between both weapons. The officer commanded the unit.

Composition of the Maschinenpistole-Trupp in 237. Infanterie-Brigade, July 1918

Personnel	Equivalent rank	Armament
1 Offizier	Commissioned officer	Pistole (P.08 or other)
1 Waffenmeisterunteroffizier	Armourer, equivalent to Sergeant
6 Gefreiter/Unteroffizier	Non-commissioned officer	Maschinenpistole (MP 18,I)
6 Mann	Private	lange Pistole (lP.08)

Each Infanterie-, Jäger-, and Schützen-Kompanie was to be assigned one M.P.-Trupp. This worked out at 6 guns per company, 24 per battalion, 72 per regiment, and 216 across the whole division. The recipients of the guns were selected at the discretion of the battalion or company commander, in a similar fashion to the distribution of the earlier lP.08 long pistol. The issue of the guns themselves to troops of an NCO rank was an official preference but not a strict requirement, and there is at least one account of a company commander temporarily assigning a gun to himself when he perceived that the situation demanded it (see 17. Armee). No guns were assigned to M.G.-Kompanies.

During the field testing stage within the 237. Infanterie-Brigade/119. Infanterie-Division, the M.P.-Trupp was to be deployed in three differing ordnance configurations in order to determine the best method by which ammunition and magazines for the MP 18,I machine pistol could be distributed. These configurations were labelled 'A', 'B', and 'C', each designed around the quantity of guns issued on a regimental basis and therefore probably assigned to the IR 46, RIR 46, and IR 58 respectively.

Equipment	'A' Configuration	'B' Configuration	'C' Configuration	Divisional Total
Maschinenpistole 18,I with cover and new type Gewehr 98 rifle sling without eyelet	72	72	72	216
lange Pistole 08 with shoulder stock, bag with carrying strap and an 8-round magazine	72	72	72	216
Magazine box with 6 drum magazines (Nürnberger pattern), with limiting sleeves, but without protective caps, along with a shortened loaders	0	216	144	360
M.G. carrying straps	0	144	72	216
Carrying bag for 5 drum magazines	144	0	72	216
Cartridge box with 5 drum magazines (Nürnberger pattern), with limiting sleeves and protective caps, a shortened loader and 480 loose rounds	216	0	72	288
Cartridge box (Patronenkasten 88) containing 5 packs of 832 pistol cartridges each	36	24	36	96
Hand cart (MG 08 pattern) with 4 pull straps	36	48	36	120
Backpacks with carrying straps	144	144	144	432
Maschinenpistole technical manual	16	16	16	48
lange Pistole 08 technical manual	16	16	16	48

In June, a training school for the machine pistol, known as the 'M.P.-Lehrkommando', was established in Mons in order to instruct the troops in the organisation and deployment of the M.P.-Truppe. Heeresgruppe Kronprinz Rupprecht was given priority as the first recipient of MP 18,I machine pistols, to be trained on these guns over the course of a four month rollout from the 18th July - 27th October. The four armies under Kronprinz Rupprecht's command (17. Armee, 2. Armee, 6. Armee, and 4. Armee) were to be issued with machine pistols in sequential deliveries once the appropriate training courses had been completed. The first army selected, the 17. Armee, issued an order on 28th of June for each of its seventeen divisions - ten infantry divisions, six reserve divisions, and one marine division - to send three men from each battalion (one comissioned officer, one non-commissioned officer, and one enlisted rank) to take a short leave of absence from their regiments and attend the M.P.-Lehrkommando at the dates arranged by the Kriegsministerium.

By the time that the first training courses for Heeresgruppe Kronprinz Rupprecht commenced in mid-July, the size of the M.P.-Trupp had been officially amended from 14 men to 5 men, issued with just 2 guns per section. The new composition comprised 1 commissioned officer, 2 non-commissioned officers, and 2 enlisted ranks. The role of the armourer was eliminated. This now meant that the rate of distribution was reduced from 6 guns to 2 guns per Infanterie-, Jäger-, and Schützen-Kompanie (8 per battalion, 24 per regiment, 72 per brigade/division). The significant reduction in the size of the M.P.-Trupp and the number of guns allocated to each company was undoubtedly the result of supply limitations for MP 18,I machine pistols and concerns that the Bergmann Waffenbau Abteilung would not be able to supply the necessary quantity of guns to support the initial projected figure of 6 guns per company.

Kronprinz Rupprecht of Bavaria himself made personal note of the adoption of the MP 18,I in his war diary. His entry for the 1st of August 1918 begins:

"Each company now initially contains two machine pistols with rifle stocks, particularly suitable for assault defense. These are essentially light machine guns, each capable of firing 36 rounds in three seconds."

The overwhelming majority of recipients will not have received any practical training in the use of the weapon and familiarisation was to take place within the regiment, as relayed by officers who had attended the M.P.-Lehrkommando in Mons. Fresh recruits were intended to be trained on the weapon via the regimental Feldrekrutendepots (Field Recruit Depots), which were to be furnished with one gun each.

Contrary to popular perception, no special emphasis was placed on the distribution of MP 18,I machine pistols to the Sturmbataillons. The Sturmbataillons were essentially training cadres to instruct regular infantry troops in the application of assault tactics and thus did not require any greater number of machine pistols. The number of guns assigned to each Sturmkompagnie was no higher than regular infantry companies - 2 guns each - and in most surviving orders and memos concerning the distribution of MP 18,I machine pistols in 1918, no mention is even given to the Sturmbataillons.

Divisions selected to attend first M.P.-Kürs at Mons [17. Armee]

1st Course (18th July - 28th July)	2nd Course (31st July - 10th August)
15. Reserve-Division 24. Infanterie-Division 185. Infanterie-Division 221. Infanterie-Division 17. Infanterie-Division 2. Garde-Reserve-Division 41. Infanterie-Division 16. Reserve-Division 5. Kgl. Bayer. Reserve-Division	187. Infanterie-Division 214. Infanterie-Division 234. Infanterie-Division 5. Kgl. Bayer. Infanterie-Division 111. Infanterie-Division 26. Reserve-Division 21. Reserve-Division 3. Marine-Division

Further courses were organised for the 2. Armee (13th August - 5th September), 6. Armee (8th September - 1st October), and 4. Armee (4th October - 27th October), though with the exception of the 6. Armee, less is known of the undertaking of these courses and which divisions were selected to attend them.

17. Armee

An order for infantry regiments to necessary arrangements to raise one M.P.-Trupp per company was circulated amongst the 17. Armee on the 19th August 1918. A copy of this order was subsequently captured by the British from the Infanterie-Regiment Nr. 126 (39. Infanterie-Division) on the 26th of August following combat at Arras.

The 17. Armee was undoubtedly the best-equipped section of the German Army for MP 18,I machine pistols during the last months of the war. The 17. Armee was given the highest priority for the distribution of the MP 18,I and by the 10th of August, its personnel had completed its training in the use of the machine pistol. By the 3rd of September 1918, thirteen of the divisions assigned to 17. Armee were equipped with the MP 18,I at a rate of two guns per infantry company (8 per infantry battalion, 24 per regiment, 72 per division).

Divisions	No. of guns	Divisions	No. of guns
21. Reserve-Division 41. Reserve-Infanterie-Brigade RIR 80 RIR 87 RIR 88	72 72 24 24 24	214. Infanterie-Division 214. Infanterie-Brigade IR 50 (3. Niederschlesisches) IR 343 IR 358	72 72 24 24 24
48. Reserve-Division 96. Reserve-Infanterie-Brigade RIR 221 (Großherzoglich Hessisches) RIR 222 (Großherzoglich Hessisches) RIR 223	72 72 24 24 24	234. Infanterie-Division 234. Infanterie-Brigade IR 451 IR 452 IR 453	72 72 24 24 24
26. Reserve-Division 51. Reserve-Infanterie-Brigade RIR 119 (Kgl. Württembergisches) RIR 121 (Kgl. Württembergisches) IR 180 (10. Württembergisches)	72 72 24 24 24	83. Infanterie-Division 165. Infanterie-Brigade IR 329 IR 330 IR 331	72 72 24 24 24
15. Reserve-Division 30. Reserve-Infanterie-Brigade RIR 17 RIR 25 RIR 69	72 72 24 24 24	3. Marine-Division Marine-Infanterie-Brigade MR 1 MR 2 MR 3	72 72 24 24 24
2. Garde-Reserve-Division 38. Reserve-Infanterie-Brigade RIR 15 (Westfälisches) RIR 77 RIR 91	72 72 24 24 24	16. Reserve-Division 31. Reserve-Infanterie-Brigade RIR 29 RIR 30 RIR 68	72 72 24 24 24
39. Infanterie-Division 61. Infanterie-Brigade IR 126 (8. Württembergisches) IR 132 (1. Unter-Elsässisches) IR 172 (3. Ober-Elsässiches)	72 72 24 24 24	111. Infanterie-Division 221. Infanterie-Brigade FR 73 (Hannoversches) IR 76 (2. Hanseatisches) IR 164 (4. Hannoversches)	72 72 24 24 24
183. Infanterie-Division 33. Reserve-Infanterie-Brigade IR 184 IR 418 RIR 440	72 72 24 24 24	Sturm-Bataillon Nr. 8 1. Sturmkompagnie 2. Sturmkompagnie 3. Sturmkompagnie 4. Sturmkompagnie	8 2 2 2 2

Several elements of the 17. Armee are known to have employed the MP 18,I machine pistol in combat amidst the German retreat during the Hundred Days Offensive (8th August - 11th November 1918). Ample references to the use of MP 18,I machine pistols by the 17. Armee during fighting around Cambrai appear in September and October 1918.

The benefit of the receipt of MP 18,I machine pistols within the 17. Armee, however, was not immediately felt owing to the dire situation which the Heeresgruppe Kronprinz Rupprecht was placed in following the failure of the Spring Offensive and the devastating British victory at Amiens. It was precisely this situation which made Kronprinz Rupprecht best placed among the German army commands to realise that victory was no longer attainable, an opinion which he voiced unsuccessfully to the O.H.L. The difficulties faced by the German divisions of the 17. Armee at this time were summarised in a letter by Klaus Hofer of the Infanterie-Regiment Nr. 132 (1. Unter-Elsässisches; 39. Infanterie-Division), who noted that the delegates of the division sent to the M.P.-Lehrkommando in Mons during August returned from their training to a regiment which had been practically decimated by the British offensives that month:

"My dear friend! I am sitting here in Monchecourt, on duty as the guard commander for the local post. Since I have plenty of time and am free to write whatever I please, I've decided to send you a long letter. A comrade of mine, who is traveling to Strasbourg on official business, will deliver it to you in person. I am doing quite well at the moment, and I hope the same is true for you. Things have been very rough lately, however. On August 26, just as I was returning from Strasbourg, the British captured my entire battalion - and the day before that, they had taken the second battalion as well. From my own company, only one sergeant and two enlisted men - out of all those who had been at the front - managed to make it back. There have been massive assaults here (on the Arras front); we were pushed back a considerable distance and lost many men as prisoners, along with a great deal of artillery. Yet, if you were to read the newspapers, you might actually think we had given the British a sound thrashing! And it's not just here - we've also had to retreat to the left, near Cambrai (where the spring offensive took place), as well as near Armentières. The enemy attacked with overwhelming force and a swarm of tanks; besides, our own soldiers are simply not what they once were. The most remarkable thing is that we are already back in position, even though our division has been effectively wiped out. As it stands, our company - comprising the few men who made it back, some returning from leave, and a handful of soldiers who had been attending a machine pistol course - now consists of just four non-commissioned officers and fourteen enlisted men! We have yet to receive any reinforcements."

The 3. Marine-Division made extensive use of their MP 18,I machine pistols during the Battle of the Canal du Nord (27th September - 1st October 1918), to varying degrees of success. An account in the memoirs of the Marine-Infanterie-Regiment Nr. 1 from one Gefreiter Baacke (3. Kompanie) describes the effective addition to company firepower that the MP 18,I provided in engaging the 1st and 4th Canadian Divisions, who on the 27th September attempted a frontal assault on Bourlon Wood:

"On the morning of September 27th, a barrage of artillery fire. We were alerted and deployed between Cantaing and Bourlon Wood, with a line of sight to the woods. We were in an artillery position, with Württemberg troops in front of us. We scrambled to spread out, as we were being shot at by German machine guns from Bourlon Wood. In the afternoon, we were ordered to counterattack between Cantaing and Anneux. We initially advanced only a short distance, as a large number of English aircraft were constantly circling overhead. Heavy fire could be heard to our left, but we could not yet see anything from the British.

We were already quite far from the village of Anneux when I spotted the English ahead. Their line was running directly towards us, but they could not see us due to the uneven terrain. We had advanced to within 30 metres of them when they noticed us because of our fire directed at their left flank. We couldn't get our light machine gun to fire because the terrain was slightly uphill. So I had a light machine gun slung over my shoulder, the others did the same, and in this way we were able to flank the Englishman with our light machine gun. We had just begun our fire in the room when the English also went up in arms and fled. We advanced further, and the English became confused. The English officers could no longer hold their men. We were now lying behind the remains of a wall and had our machine guns and machine pistols in action. The English fled in small groups. If the Württembergers, to whom we had attached ourselves, had still been there, we would have captured the whole group. It was beginning to get dark, and we were in danger of being surrounded on the right. I wanted to get a few more Englishmen who were a little ahead of us and couldn't retreat, but the others stopped me."

By the 29th of September, the MIR 1 had fallen back to Noyelles-sur-Escaut on the outskirts of Cambrai. The MIR 1 took heavy losses on this day, resulting in the destruction of the regiment's I. Bataillon. The commander of 4. Kompanie, Leutnant Rinder, described the punishing conditions faced by the regiment during this battle, which in many ways prevented the MP 18,I from making a notable impact:

"As it grew light, I had just enough time to secure the manning of the trench; there was no time left for another patrol towards the enemy. I had to assume that the enemy was on this side of the canal bank. I ordered two heavy machine guns to take up a higher position behind the line and to prepare my three light machine guns for firing. The machine pistols were switched to the old saps forward. I couldn't create a staggered formation for my position, as that would have exposed too large a stretch. The men were overworked and exhausted. In the lower-lying areas, especially in the canal bed, there was thick fog at daybreak. My visibility was about 250 metres.

Around 7:30 a.m., the enemy artillery began to increase. My left wing Unteroffizier came running with the report that the elements of the IR 64, to our left, were retreating towards Masnières. Since I had clear orders to hold this position to the last man, and there was no sign of the enemy yet, I ordered the left flank group to increase their vigilance and to link up with the 3. Kompanie by patrolling. Meanwhile, our position was under very well-directed artillery fire. The trench took several ricochet hits, and sorties were occurring. Unteroffizier Rothärmel, one of the oldest and most capable NCOs in the company, reported to me that his light machine gun was no longer operational, and a machine pistol had also failed. This was another serious setback to our fighting strength. I deeply regretted that we had had to take up our position in front of the Hagen Line. There, at least, would have been some barbed wire obstacle. Now we had no barbed wire entanglements whatsoever in front of us. Plöhlich saw dense English skirmish lines appear at a distance of about 250 metres, followed by dense columns. The order was now, "to hold the position to the last man.""

The costly battles during the fighting around Cambrai severely reduced the fighting capability of the 17. Armee's divisions, and it appears that in some regiments, machine pistol losses were disproportionately high compared to other materiel, presumably because the company M.P.-Truppe were habitually assigned to forward positions. By the 9th October 1918, the Marine-Infanterie-Regiment Nr. 2 reported only having three MP 18,I machine pistols remaining across the entire regiment, compared to eight MG 08 medium machine guns and eighteen MG 08/15 light machine guns. The 3. Marine-Division was transferred to the 18. Armee later in October where it would see further action at the Battle of the Selle (see: Heeresgruppe Deutscher Kronprinz).

Another vivid first-hand account of the weapon's use in combat during the war comes from the official memoir of the Kgl. Württembergisches Reserve-Infanterie-Regiment Nr. 119 (26. Reserve-Division) which describes an abortive German counterattack against the advancing Canadian Corps on the 1st October 1918 - the final day of the Battle of Canal du Nord - in which the MP 18,I was employed by Leutnant Eugen Rettenmaier during an assault against a stubborn Canadian position:

"Around 4 o'clock in the afternoon, the German counterattack north of Ramillies got underway. As the firing lines reached and attempted to cross Hill 78, 4km east of Tilloy, German fire struck their ranks, causing hesitation and confusion, so that the attack recoiled back to its starting position. An enemy machine gun on this hill continuously harassed the reserves behind Morenchies and prevented movement and communication. A fleeing Englishman sought cover behind the embankment that concealed it. This was observed by Leutnant Eugen Rettenmaier, the commander of 5. Kompanie, who, with his walking stick in his hand, was helping to recover wounded Englishmen. "He'll be taken care of later!" he said to his men.

A somewhat muddled account likely referring to an MP 18,I machine pistol also appears in the memoir of the Reserve-Infanterie-Regiment Nr. 80 (21. Reserve-Division), again during fighting in early October 1918 near Cambrai, as recalled by Unteroffizier Paul Schlieger (8. Kompanie, 4. Pioniere):

"Approximately 200 - 300 metres to our left lay another farmhouse, which was apparently still occupied by the enemy. To investigate, Gefreiter Anton Heinz and I advanced further, while the company's comrades remained in the hollow way, covering us with our rifles at the ready. If we reached the farmstead unchallenged, the company would follow. A riddled building lay beside a field path leading to the estate, of which only the foundations remained. It seemed to me that something was moving among the ruins.

We approached with our rifles at the ready and, to our surprise, found a whole group of Englishmen in the still well-preserved cellar. A sergeant and eight men crawled out with their hands raised. All but one had already unbuckled their leathers, and even this one couldn't tear them off quickly enough when I made an unmistakable gesture with my rifle. We signaled to our prisoners that they should slink away. The two of us then thoroughly examined the cellar and found many nice and useful items in the Tommies' luggage, things that had unfortunately become very rare on the German side in the fourth year of the war. Among other things, I discovered a brand-new German M.G.-pistol 08/15 with 45 rounds of ammunition in a knapsack. Since my own pistol had gone missing just a few days earlier, this find gave me particular pleasure."

The reference to an 'M.G.-Pistole 08/15' is clearly a conflation in terminology of both the MP 18,I machine pistol and the MG 08/15 light machine gun, though the context under which the weapon is described as being used as a replacement for Schlieger's missing pistol indicates that the weapon was probably an MP 18,I. The presence of this weapon within a British forward position also raises an interesting implication - though no doubt this was a recent capture from German troops during the British advance, could these British soldiers have kept it for their own use? There is no definitive record of Allied troops making use of captured MP 18,I machine pistols during the war, though it is certainly not implausible that there may have been isolated incidents of 'Tommies' making temporary use of captured guns.

The 17. Armee may possibly have loaned a small number of MP 18,I machine pistols to the 6. Armee in October 1918, owing to delays in the delivery of guns to the front during this final stage of the war.

2. Armee

Despite being included in the initial schedule for the M.P.-Lehrkommando, with training courses arranged for 13th - 23rd August (1st course) and 26th August - 5th September (2nd course), no data is currently available concerning the actual distribution of MP 18,I machine pistols to the 2. Armee. Machine pistol figures for the 2. Armee are omitted from the distribution memorandum of 3rd September 1918 compiled by Heeresgruppe Kronprinz Rupprecht, as at that time the 2. Armee had been grouped with the 18. Armee to form the short-lived Heeresgruppe Boehn from the 12th August. This was disbanded on the 8th October and the 2. Armee was subsequently transferred back under the command of Kronprinz Rupprecht until the end of the war, though remained situated directly alongside the 18. Armee throughout the final battles on the Western Front.

The first recorded use of MP 18,I machine pistols in combat occurred within the 2. Armee, by the 119. Infanterie-Division who had received the first batch of guns for field testing. On the first day of the the Battle of Amiens (8th - 12th August 1918), the 119. Division was transferred from the 18. Armee reserve to the 2. Armee, and deployed around the town of Le Quesnel on the 9th August. Initially, the 119. Division achieved notable success with the MP 18,I; the Infanterie-Regiment Nr. 58 (3. Posensches) repelled an attack by the British 1st Cavalry Division on the nearby village of Maucourt using their machine pistols. However, when the 1st Cavalry Division was relieved by the 3rd and 4th Canadian Divisions later in the day, the 119. Division was forced to withdraw and Le Quesnel was captured by the Canadian Corps, resulting in the loss of several machine pistols. Continual losses of the 119. Division's machine pistol strength occurred throughout the battle.

Though second in priority for the receipt of MP 18,I machine pistols, the actual delivery of these guns to the infantry divisions comprising the 2. Armee appears to have occurred very late in the war; perhaps only days from the armistice. The Reserve-Infanterie-Regiment Nr. 94 (22. Reserve-Division) referred to the use of "machine pistols which had just arrived" during the Battle of the Sambre (4th November 1918), curiously assigned to an anti-aircraft role in defending rear artillery emplacements from low-flying aircraft - presumably in order to free up the regiment's light machine gun strength at the front.

Likewise the memoirs of the Kgl. Württembergisches Infanterie-Regiment Nr. 413 (204. Infanterie-Division) only make mention of their use of the MP 18,I in November of 1918, describing what was likely the final combat use of the MP 18,I machine pistol during the war, during a skirmish near the Belgian border on Armistice Day:

"On November 11, 1918 – it had just become light – another patrol of the regiment advanced in the general direction of Maubeuge to determine if and where the British were following. The patrol – which, as far as I recall, consisted of Leutnant (Reserve) Stefan and 5-6 men – advanced several mileage without encountering the enemy. Suddenly, they spotted a fairly strong enemy cavalry patrol, which was almost completely wiped out by Stefan's patrol, whose men were equipped with machine pistols. This was the last combat activity of the regiment and probably also of the division, because while the patrol was still in no man's land, news arrived that the armistice had been concluded and hostilities were to cease at noon. One would think that this news would have caused joy and jubilation, especially after all the hardship of the past few weeks, but the opposite was true. Dejected, the people discussed the event, and only the awareness of having resisted the enemy to the very last second in the utmost fulfillment of duty and of having kept the horrors of war and its sad consequences away from our beloved homeland allowed us to overcome the bitterest hour of our soldiers' lives."

Divisions	No. of guns
119. Infanterie-Division 237. Infanterie-Brigade IR 46 (1. Niederschlesisches) RIR 46 IR 58 (3. Posensches)	216 216 72 72 72

6. Armee

The 6. Armee was third in priority to receive MP 18,I machine pistols, with its delegates from its divisions scheduled to receive training at the M.P.-Lehrkommando from the 8th - 18th September (1st course) and 21st September - 1st October. The Armee-Oberkommando 6 (A.O.K. 6) drew up a list of ten divisions which were to receive MP 18,I machine pistols once the necessary training had been completed.

The divisions of the 6. Armee intended to receive MP 18,I machine pistols following this training course were as follows:

Divisions	No. of guns	Divisions	No. of guns
38. Infanterie-Division 83. Infanterie-Brigade IR 94 (5. Thüringisches) IR 95 (6. Thüringisches) IR 96 (7. Thüringisches)	72 72 24 24 24	4. Ersatz-Infanterie-Division* 13. Ersatz-Infanterie-Brigade IR 360 IR 361 IR 362	72 72 24 24 24
12. Kgl. Bayer. Infanterie-Division 22. Kgl. Bayer. Infanterie-Brigade Kgl. Bayer. IR 26 Kgl. Bayer. IR 27 Kgl. Bayer. IR 28	72 72 24 24 24	36. Infanterie-Division 71. Infanterie-Brigade Gren.R 5 (4. Ostpreußisches) IR 128 (Danziger) IR 175 (8. Westpreußisches)	72 72 24 24 24
5. Kgl. Bayer. Infanterie-Division 10. Kgl. Bayer. Infanterie-Brigade Kgl. Bayer. IR 7 Kgl. Bayer. IR 19 Kgl. Bayer. IR 21	72 72 24 24 24	16. Infanterie-Division 30. Infanterie-Brigade IR 28 (2. Rheinisches) IR 29 (3. Rheinisches) IR 68 (6. Rheinisches)	72 72 24 24 24
9. Reserve-Division 18. Reserve-Infanterie-Brigade RIR 6 RIR 19 IR 395	72 72 24 24 24	8. Infanterie-Division 16. Infanterie-Brigade IR 72 (4. Thüringisches) IR 93 (Anhaltisches) IR 153 (8. Thüringisches)	72 72 24 24 24
2. Garde-Reserve-Division* 38. Reserve-Infanterie-Brigade RIR 15 (Westfälisches) RIR 77 RIR 91	72 72 24 24 24	12. Reserve-Division 22. Reserve-Infanterie-Brigade RIR 23 RIR 38 RIR 51	72 72 24 24 24

*Transferred from the 17. Armee; already trained and issued with the MP 18,I.

Though this course was undertaken, there is evidence that the guns intended for the 6. Armee were either delivered late or never at all. A telegram from the Artilleriedepot Karlsruhe Baden to the A.O.K. 6, dated 23rd October 1918, reports that the machine pistols allocated to the 6. Armee had been awaiting delivery since the 9th October but no action had yet been taken by the A.O.K. 6 to arrange their collection. In the meantime, the A.O.K. 6 requested the loan of 16 machine pistols from the 17. Armee. By this time, it was far too late for German troops to glean any advantage from the receipt of MP 18,I machine pistols, and the armistice would be signed just 19 days later.

The 2. Garde-Reserve-Division, who had been issued with MP 18,I machine pistols while serving under the 17. Armee in August, were transferred to the 6. Armee on the 5th of September 1918 and were posted on the outskirts of Lille opposite the British Fifth Army. On the first day of the Fifth Battle of Ypres (28th September - 2nd October 1918), the division's Reserve-Infanterie-Regiment Nr. 91 employed the MP 18,I in repelling an attack by British troops at Neuve-Chapelle on the 28th September 1918. This action was described by Leutnant Nebauer, the commanding officer of the regiment's 3. Kompanie:

"Soon after it became quiet again, and I was just about to go forward to see if anything had happened, a man from the first platoon came breathlessly up the trench and shouted from a distance: "The first trench is full of Englishmen!" At first, I couldn't believe my ears. In broad daylight? At midday, when the sun was blazing down on the battlefield? But in war, there's not much time for deliberation. It's all about action. Trusting in my own brave company, I refrained from requesting assistance from the battalion commander, called up the third platoon, which was designated as a Stoßtrupp for such situations, and attacked. Two light machine guns from the Stoßtruppe and one light machine gun from the second platoon, positioned at a staging point between the front line and the main battle line, flanked the enemy in the trench they occupied, while the Stoßtrupp itself, reinforced by part of the second platoon, pressed forward.

The English had occupied the trench to the right. Vizefeldwebel Geese, with his first platoon, had, as ordered, withdrawn to the left during the enemy attack, as was often practiced during periods of respite. When he saw us approaching in the trench, he and his platoon immediately joined our assault force. From shoulder to shoulder, we rolled up the trench to the right, pushing back the enemy, who were firing heavily on us and throwing hand grenades. Those Englishmen who fled from the trench again received heavy fire from cleverly positioned light M.G.s and M.G.-Pistols and suffered heavy losses. Many did not reach the English trench again. We captured two wounded enemy soldiers, a machine gunner, and other weapons. In an hour, it was all over; the trench was back in our hands."

Vizefeldwebel Geese won the Iron Cross First Class for his actions on this day.

Later on the 2nd October, the final day of the battle, the RIR 91 were ordered to reposition from Englos to Armentières. The regiment made effective use of a small force of men armed with MP 18,I machine pistols to hold back the British advance whilst the rest of the battalions withdrew safely, as explained by Leutnant R. Steinberg:

"Had we carried out the order as it was given, we certainly wouldn't have been able to get our companies out of the position unharmed. We therefore decided to let the companies withdraw, while we, the company commanders, each with a strong patrol and pioneer detachment, remained in the trench. We kept our recently issued machine-gun pistols and, by constantly moving around and firing them, feigned a strong M.G. arsenal. Only when the companies had passed through the barrage zone did we begin blowing up the position. Immediately, as we had correctly suspected, the British gas barrage began, but Tommy didn't dare attack. Then we, too, withdrew undetected by the enemy, blew up the dugouts in the second line, as well as the crossroads at Halpegarbe, and, using gas masks, got through without losses."

The Reserve-Infanterie-Regiment Nr. 77, also of the 2. Garde-Reserve-Division, similarly made extensive use of their machine pistols during the Allied advanced into Belgium in October 1918. On the 16th of that month, amidst the ongoing Battle of Courtrai (14th - 19th October 1918), the RIR 77 was engaged against the British Fifth Army on the outskirts of Tournai, where one soldier armed with an MP 18,I machine pistol earned the Iron Cross First Class for his quick reaction to an attempted British advance in this sector:

"Today, Musketier Mozek of the 6. Kompanie, RIR 77 - a machine pistol gunner patrolling the canal - noticed sounds coming from the western bank. He immediately lay in wait and spotted a few British soldiers who appeared to be digging in. He opened precise fire on the enemy, wounding one of them, but then held his position quietly. When Mozek noticed others rushing to the wounded man’s aid to bandage him, he alerted his nearby comrades. Musketiere Schwark and Lange immediately volunteered to capture the men on the other side. While Mozek and other comrades (Unteroffizier Rindschädel, Gefreiter Schiemann, and Musketier Otto Meyer) pinned down the enemy with machine-gun fire and prevented reinforcements from arriving, Schwark and Lange crossed the canal on planks, attacked the enemy, and returned with three British prisoners from the 74th Division."

On the morning of the 20th October, troops from the regiment's 5. Kompanie made use of light machine guns and machine pistols in establishing an ambush against a scouting patrol of British cavalry approaching a farmstead outside of Orcq:

"At 9:40 a.m., five mounted English soldiers emerged from Marquain and initially halted on the road to Orcq. Then, four of the Englishmen rode on toward Orcq, while one remained at the eastern exit of Marquain. One halted at the eastern exit of Marquain. The officer's patrol from the 5. Kompanie, which I was accompanying, had immediately spotted the Englishmen. The leader, Offizier-Stellvertreter Meier, issued practical orders. Above all, the enemy was to be allowed to approach as closely as possible; then, upon a whistle signal from him, fire was to be opened simultaneously by a light machine gun, a machine pistol, and the rifles. The two leading riders had come within 150 metres of the farmstead - located 100 metres west of Orcq - when fire opened immediately upon the agreed signal. The first two horses went down instantly, while the two that were slightly further back fell just outside Marquain."

It is likely that the only other division within the 6. Armee to deploy the MP 18,I in combat was the 4. Ersatz-Infanterie-Division, also transferred from the 17. Armee. The 4. Ersatz-Infanterie-Division, along with the 2. Garde-Reserve-Division, remained with the 6. Armee until the end of the war.

4. Armee

The 4. Armee was the fourth and lowest army in priority for the distribution of MP 18,I machine pistols within the Heeresgruppe Kronprinz Rupprecht. The training courses for the divisions of 4. Armee took place from 4th – 14th October (1st course) and 17th – 27th October (2nd course). The likelihood of any guns being delivered to the rest of the 4. Armee before the armistice of the 11th November, however, seems slim. No guns had been assigned to the 4 Armee at all by the 3rd September, and the projected completion of their machine pistol training by the 27th October leaves very little time for a full delivery of MP 18,I machine pistols to be made and issued to the front before the armistice.

Several divisions transferred from the 17. Armee to the 4. Armee after August were likely the only divisions assigned to this army to possess machine pistols. These included the 40. Infanterie-Division, which was transferred to the 4. Armee in early September. The official history of the division’s Infanterie–Regiment 'Kronprinz' Nr. 104 (5. Kgl. Sächs.) confirms that the regiment despatched a delegate, Leutnant Grünert, to the M.P.–Lehrkommando in Mons. A description of the MP 18,I is also given in the chapter 'The Development of Mortars and Infantry Close–Combat Weapons in the Regiment':

"Another valuable addition to the M.G. for assault defense was the invention of the machine pistol in the later months, which, due to its light weight, allowed for standing, unsupported firing. The 32 rounds in its drum magazine could be fired in 3.5 seconds. Because our enemies are aware of the effectiveness of these weapons, they are no longer permitted in the inventory of the new Reichswehr."

Among the other divisions transferred from the 17. Armee to the 4. Armee after August was the 6. Kgl. Bayer. Infanterie–Division, the unit in which Adolf Hitler was serving.

Heeresgruppe Deutscher Kronprinz

Only incomplete records can be sourced on the use of the MP 18,I machine pistol by German divisions assigned to the Heeresgruppe Deutscher Kronprinz, comprising the 18. Armee, 7. Armee, 3. Armee, and 1. Armee. Evidence indicates that Heeresgruppe Deutscher Kronprinz was trained on the MP 18,I machine pistol concurrently with Heeresgruppe Kronprinz Rupprecht, though the order in which the relevant armies were selected to receive training and weapons is currently not certain.

18. Armee

The first MP 18,I machine pistols delivered to the 18. Armee were those distributed to the 119. Infanterie-Division for field testing; however these were likely not used in combat until the 119. Division transferred to the 2. Armee of Heeregruppe Kronprinz Rupprecht on the 9th August 1918. The 18. Armee and 2. Armee were brought together under the Heeresgruppe Boehn from the 12th August, though this union was short-lived and by the 8th October, the 18. Armee was reassigned to the Heeresgruppe Deutscher Kronprinz. It is not known to what extent the formation and disbandment of Heeresgruppe Boehn affected the existing schedules for machine pistol training and issue.

The 18. Armee was likely given the highest priority for the delivery of MP 18,I machine pistols within the Heeresgruppe Deutscher Kronprinz. The divisions of the 18. Armee had possibly been equipped with machine pistols by the time of the Battle of the Selle (17th - 25th October 1918), as several guns were captured by the British Fourth Army engaged against elements of the 18. Armee around Wassigny, including the 5. Reserve-Division and 24. Infanterie-Division (Kgl. Sachs.); though this sector was also defended by recently transferred elements from the 17. Armee which had already been issued with the MP 18,I, including the 3. Marine-Division and 15. Reserve-Division, who may also have been the source of the guns encountered by the Fourth Army.

3. Armee

Evidence that the 3. Armee were called on to send delegates to attend the M.P.-Lehrkommando in Mons exists in the form of a letter written by a Leutnant of the Landwehr-Infanterie-Regiment Nr. 116 from Feldpost Nr. 35 (the mail address of the M.P.-Lehrkommando), which was sent to a fellow officer of the regiment on the 24th September 1918. The recipient officer was subsequently captured by the French in October and an excerpt of this letter was reproduced in a French memorandum, issued on the 11th October 1918:

"We are going to take a course of instruction on the new weapon in the Army of Crown Prince Wilhelm [...] I think this new weapon is excellent. It has many advantages over the light machine gun, fires 96 shots in 30 seconds. The weapon is lighter than the Model 98 rifle."

The date of this course seems to coincide with that of the 6. Armee of Heeresgruppe Kronprinz Rupprecht. Whether the 3. Armee also experienced delays in the receipt of these weapons as the 6. Armee did is not known. Nonetheless it is unlikely that they received any guns earlier than October under the timeframe of their training course, and evidently the French Army had not encountered any examples in service with the LIR 116 at the time that the above letter was captured.

Other Army Groups

There is currently no known record that MP 18,I machine pistols were ever distributed to Army Groups other than Heeresgruppe Kronprinz Rupprecht or Heeresgruppe Deutscher Kronprinz before the end of the war in November 1918. Given that an order of 50,000 guns was placed, it is almost certain that distribution of the MP 18,I was intended to stretch across the entire German infantry, however it is currently unclear whether any M.P.-Lehrkommando courses were ever established outside of Mons and there is no known mention of the use of machine pistols in the memoirs of any regiments outside of the 17. Armee and 2. Armee.

For most German infantry divisions in late 1918, the Luger P.08 and lP.08 remained the primary close-combat armament of the assault troops and pioneers. The official memoir of Badisches Leib-Grenadier-Regiment Nr. 109 (28. Infanterie-Division, Heeresgruppe Gallwitz) explains that "The machine pistol, completed in the autumn of 1918, in which shots followed each other automatically like a machine gun, was not issued to our regiment. Along with hand grenades, pistols were the standard equipment for assault troops during patrol operations and when clearing trenches."

'Old style' markings

A rare and non-standard style of typeset can be observed on the magazine housing of very early examples of the MP 18,I. This 'old style' pattern of marking has been observed on serials № 2, № 21, and № 130, but had evidently ceased by № 193.

The 'old style' typeset, probably etched by hand, was likely only carried out on pre-production guns made for the trial stage of development. It aligns very closely to the typeset seen on late production examples of the LMG 15 n./A. machine gun, also manufactured at the Bergmann Abteilung Waffenbau. Once full production of the MP 18,I had commenced by May 1918, the identifying marks and serial numbers were stamped onto the magazine housing and receiver in a simplified typeset, hastening the process.

Regimental and company markings on weapons issued to the IR 46

At least four surviving examples of the MP 18,I bear regimental stamps on the buttstocks, all of which belong to the Infanterie-Regiment Nr. 46. The initials 'J.R.46.'* are accompanied by two other abbreviated markings, a 'K.' stamp and either a 'P.' or an 'N.' stamp, all of which are numbered. There is no known documentation which explains the precise meaning of these stamps, or why they were added.

It can be reasonably inferred, however, that since M.P.-Trupp squads were assigned on a company level, the 'K.' stamp stands for 'Kompanie', with the associated number identifying the specific company (i.e. '1.K.' = '1. Kompanie/1st Company'). The highest identified 'K.' stamp is 'K.12.', which is entirely consistent with the number of infantry companies within the IR 46 (12 companies across 3 battalions).

The meaning of the 'P.' or 'N.' stamp is less clear. These initials never appear together on the same gun, but seem to serve the same purpose as they are located after the 'K.' stamp. The most likely explanation is that these initials are intended to serialise the number of guns within each individual company; for instance, '1.K. P.1.' would denote the first gun of 1. Kompanie, '1.K. P.4.' would denote the fourth gun of 1. Kompanie, and so forth. If this is correct, then the 'P./N.' stamps would range from 1 - 6, for the 6 guns assigned to each infantry company.

Why this stamp alternates between using the initial 'P.' and 'N.' is less clear. The initial 'P.' is only observed on guns in the possession of 1. Kompanie, whereas the initial 'N.' is seen on guns possessed by 3. Kompanie and 12. Kompanie. It is possible that 'P.' stands for 'Pistole', whereas 'N.' stands for 'Nummer', effectively conveying the same meaning but using different terms.

The inconsistency in both the lettering and layout of the markings might suggest that they were not all created by the same hand. They might have been added on an individual basis by the armourers or officers assigned to each infantry company within the IR 46. The armourer of 1. Kompanie may have preferred the use of the initial 'P.' for 'Pistole', whereas the armourer of the 3. and 12. Kompanies may have preferred 'N.' for 'Nummer'. The markings being added by individual company officers is supported by the fact that the markings of the guns possessed by the 1. Kompanie clearly adhere to a different format than the guns possessed by the 3. and 12. Kompanies.

The intent of adding these markings in the first place was likely to tightly control the number of weapons assigned to each company during the field testing stage, identify missing guns, and ensure that lost guns were returned to the IR 46 if recovered by other German regiments. That there are no known regimental stamps beyond those of the IR 46 indicates that the practice was confined to early field testing of the MP 18,I, and was no longer deemed necessary after the main rollout of weapons across other divisions in August 1918. Additionally, the practice was likely unique to the IR 46; no similar stamps belonging to the RIR 46 and IR 58 (the other participant regiments in the field testing stage) have been discovered.

Serial	Regimental stamp & layout	Probable meaning
№ 136	J.R. 46 12.K. N.6.	Infanterie-Regiment 46, 12. Kompanie, Nummer 6
№ 146	1.K. P.2. J.R.46.	1. Kompanie, Pistole 2, Infanterie-Regiment 46
№ 193	J.R. 46. 12.K. N.3.	Infanterie-Regiment 46, 12. Kompanie, Nummer 3
№ 377	1.K. P.4. J.R.46.	1. Kompanie, Pistole 4, Infanterie-Regiment 46
Unknown	J.R.46. 3.K. N.4.	Infanterie-Regiment 46, 3. Kompanie, Nummer 4

*In contemporary German typology, the letter 'I' was often written as a 'J'. The use of 'J' here does not imply 'Jäger-Regiment'.

Provenance of selected captured guns

Several examples of the MP 18,I machine pistol which exist in British and Canadian museums today possess provenance which can be traced back to the final months of the First World War. Most of the trophy weapons are connected to two major engagements in 1918, the Battle of Amiens (8th - 12th August) and the Battle of the Selle (17th - 25th October), obtained from German divisions assigned to the 2. Armee and 18. Armee. Among these, several likely came from divisions which had received MP 18,I machine pistols while attached to the 17. Armee in August 1918, but had since been transferred to the 18. Armee.

As of yet, no guns with provenance linked to American or French troops have been identified. None of the serial numbers of these trophy weapons exceed № 2000.

Serial	Captor	German Division	Date/Location
№ 146	Unrecorded Canadian Division	Infanterie-Regiment Nr. 46 119. Infanterie-Division 2. Armee	8th - 12th August 1918 Amiens (Battle of Amiens)
№ 193	2nd Canadian Division Fourth Army	Infanterie-Regiment Nr. 46 119. Infanterie-Division 2. Armee	8th - 12th August 1918 Amiens (Battle of Amiens)
№ 214	Unrecorded British/Canadian Division	Unknown	Before 12th September 1918
№ 216	75th Canadian Battalion 4th Canadian Division Fourth Army	119. Infanterie-Division 2. Armee	9th August 1918 Le Quesnel (Battle of Amiens)
№ 1004	50th Northumbrian Division Fourth Army	Unknown	Unknown
№ 1603	Machine Gun Corps 46th Division Fourth Army	5. Reserve-Division (probable) 18. Armee	17th October 1918 Regnicourt (Battle of the Selle)
N/A	1st Battalion King's Shropshire Light Infantry 6th Division Fourth Army	15. Reserve-Division/3. Marine-Division (probable) 18. Armee	17th October 1918 Busigny Wood (Battle of the Selle)

Serial № 216

This gun was one of four captured by the 75th Battalion (Canadians) on the 9th of August 1918, during the Battle of Amiens (8th - 12th August). It was claimed by the battalion's commanding officer Lieutenant Colonel Colin Clark Harbottle. This gun almost certainly belonged to the 119. Infanterie-Division, who on the 9th August were positioned just outside of Le Quesnel, along with elements of the 225. and 192. Infanterie-Divisions. It is unclear, however, whether the gun was obtained from the IR 46, RIR 46, or IR 58. Today this weapon is kept at the Toronto Scottish Regiment Museum.

Lt. Col. Harbottle's actions during the war redeemed him from the public disgrace he had suffered a decade prior; in 1908 he had been convicted of embezzling over $14,000 and served a two-year prison sentence.

Serial № 1004

This gun was obtained in 1918 by Padre Robert Wilfrid Callin, the Chaplain of the 149th (Northumberland) Brigade, 50th Northumbrian Division. As part of the Fourth Army, the 50th Division participated in the Hundred Days Offensive and fought at the battles of Cambrai and the Selle, where this gun was likely captured. As a non-combatant, it is unclear how Callin specifically came into possession of this gun, though it may have been given to him by an officer of the division as thanks for his services to the 149th Brigade. This gun today is kept at the Manx Museum on the Isle of Man.

Serial № 1603

This gun was captured by Captain George Albert Wade of the 46th Battalion Machine Gun Corps, 137th (Staffordshire) Brigade, 46th Division, during fighting at Regnicourt on the 17th of October 1918, the first day of the Battle of the Selle. The official history of the Fourth Army records that the 46th Division were primarily engaged against the 5. Reserve-Division (18. Armee) on this day, capturing 15 officers, 500 troops, and over 100 machine guns.

Unknown serial

This gun was captured by the 1st Battalion King's Shropshire Light Infantry, then attached to the 6th Division, during fighting at Busigny Wood, near Andigny les Fermés, on the 17th of October 1918. This sector was defended by the I. Bayerisches Armeekorps of the 18. Armee. The official history of the Fourth Army records that the 6th Division was engaged against elements of the 15. Reserve-Division, 3. Marine-Division, and 24. Infanterie-Division (Kgl. Sächs.). All of these divisions had recently transferred to the 18. Armee from the 17. Armee, where it is known that the 15. Reserve-Division and 3. Marine-Division had been trained and issued with MP 18,I machine pistols; this is also likely of the 24. Infanterie-Division.

German and Allied assessments of the MP 18,I

The German Army appears to have been largely satisfied with the performance of the MP 18,I at the front. The feedback of the field testing conducted by 119. Infanterie-Division was compiled into a report by the O.H.L., a summarised copy of which was sent to Heeresgruppe Kronprinz Rupprecht on 18th September 1918. The overall function of the weapon's firing action and ballistic efficacy was deemed adequate, though flaws were detected in the design of the TM.08 magazines and the magazine feed itself.

"The machine pistol has proven itself very effective in patrol engagements and on field patrol due to its high accuracy and immediate readiness to fire.

A major advantage over the light machine gun is that the machine pistol can be used in any firing position and, due to its low weight, is easy and quick to handle. The machine pistol case is considered cumbersome. It is best left behind during movement. The magazine loader and spare parts are then carried in a pouch (tent pole pouch) on the belt. In this way, each pistol and magazine ammunition carrier can carry five loaded 32-round magazines, as well as 800 loose rounds.

Malfunctions were sometimes caused by the magazine lips being too sharp and easily bending, allowing metal shavings from the cartridge cases to fall into the chamber and obstruct its movement. On some magazines, the magazine catch does not engage in the notch on the neck of the magazine.

No particular lessons of value for training have been learned. The aforementioned malfunctions can be easily remedied by a gunsmith or by replacing the magazine."

The problems reported in the magazine feed of the MP 18,I may have served as an impetus for the development of the subsequent models MP 18,III and MP 18,IV (see Experimental variants II, III, & IV), both of which employed improved feed systems which replaced the TM.08 drum magazine with a more reliable rectangular box magazine and eliminated the need for a magazine collar. However, there is no indication that the German Army intended to interrupt the existing production of MP 18,I machine pistols with a new model during the war.

Brigadier-General Victor Odlum and other officers of the 2nd Canadian Infantry Division inspecting a captured MP 18,I machine pistol at the
Battle of Amiens, 13th August 1918 - one of the first such guns ever issued and probably the first captured by the Allies.
(Libraries and Archives Canada)

From August, the Allied armies began to encounter both written references and physical examples of the MP 18,I. The earliest confirmed encounters with the gun at the front appear during the Battle of Amiens (8th - 12th August 1918) by the Canadian Expeditionary Force. The post-action report of the 13th Canadian Battalion (Royal Highlanders of Canada; 1st Canadian Division) describe the use of MP 18,I machine pistols by the Germans on the 8th August, probably the first written record of the gun by Allied troops. The 75th Canadian Battalion (4th Canadian Infantry Division) captured four guns from the 119. Infanterie-Division during fighting at Le Quesnel on the 9th August. In the aftermath of the battle, Brigadier-General Victor Odlum of the 2nd Canadian Infantry Division was photographed examining a captured MP 18,I machine pistol, surrounded by his staff officers.

On the 20th August 1918, a French flamethrower section of the 1/40e bataillon (1er régiment du génie) captured 9 guns described as 'mitraillettes' during an action near Vassens, a sector defended by the German 202. and 222. Infanterie-Divisions (9. Armee, Heeresgruppe Boehn):

"August 20 – Sergent Fréquelin, assigned to the 110e régiment d'infanterie, is tasked with clearing the 'Kakadu' bunker north of Vassens. The attack is set for 7:15 a.m. The group captures 5 mitrailleuses, 9 mitraillettes, and approximately 150 men."

The term 'mitraillette' in modern French is understood to mean machine pistol or submachine gun, though given that this class of weapon did not yet exist in contemporary French military doctrine, it is unclear whether the term was applied here to refer to the MP 18,I machine pistol. More likely it is intended to be referring to a 'small' machine gun such as the MG 08/15, as opposed to the full-sized MG 08 'mitrailleuse'. It remains possible, however, that some elements of the 9. Armee had been issued with the MP 18,I concurrently with the 17. Armee; though there is no known documentation to confirm this.

British intelligence was first made aware of the existence of the MP 18,I through the capture of a set of orders from the IR 126 (8. Württembergisches) during fighting at Arras in late August. In fact, the aforementioned 2nd, 3rd, and 4th Canadian Infantry Divisions had already captured several examples of the MP 18,I at Amiens, but this had apparently not yet been appreciated by the General Headquarters. On the 26th August, the General Headquarters Intelligence issued a bulletin detailing the distribution of machine pistols to German divisions of the 17. Armee, enclosed with a translated copy of another captured order from the RIR 121 (26. Reserve-Division), which detailed the formation of M.P.-Trupp sections within each infantry company, and also makes it clear that the wooden ammunition chests (P.-Kasten) with 480 rounds had been adopted for general issue as opposed to the experimental canvas magazine bags which had been used by the IR 46.

"ALLOTMENT OF AUTOMATIC PISTOLS TO INFANTRY COMPANIES.

A captured order of the one-hundred and twenty-sixth infantry regiment (thirty-ninth division), dated August 19, 1918, states at an automatic pistol section (Trupp) is to be allotted to each infantry company. The section will be armed with two automatic pistols (Maschinen Pistole '18 I.)

The order states further that a course of instruction in the use of the automatic pistol, lasting twelve days, will shortly be held under the supervision of the regiment. Each infantry company is to send a capable N.C.O. to be trained as section commander and four active young men, including, if possible, two lance-corporals. It would appear from this that the personnel of an automatic pistol section will be one N.C.O. and four lance-corporals and men (one lance-corporal and one man per pistol).
It was already known from captured documents that a course of instruction in the use of the automatic pistol had been taking place at Mons. No details of the weapon are known and prisoners should be examined on the subject. It is desirable that a specimen of the pistol should be forwarded to G.H.Q. "I," as early as possible.
GENERAL STAFF (Intelligence),
General Headquarters, August 26, 1918.

GERMAN AUTOMATIC PISTOLS.

(a) An order of the one-hundred and twenty-first reserve infantry regiment, dated 19-8-18, contains the following:

Automatic Pistol.

(i) Issue to companies: Two pistols and 6 boxes of ammunition, each containing 480 rounds (15 drums). These are to be used for purposes of training. Only half of a drum will be fired at a time.

(ii) The automatic pistol is a regular "bullet squirt" (Kugelspritze) and is well adapted for hand-to-hand fighting. It must, however, be entrusted to only skilled marksmen. All officers, platoon and patrol commanders and, for the present, six men per company taken from rifle sections (not machine gun sections), will be trained in its use.

(b) Eight men of the two-hundred and twenty-second reserve infantry regiment, forty-third reserve division,* were sent away recently for a 10 day's course for this pistol, which has now been issued on the scale of 2 per company."

*(Mistranscription of 48. Reserve-Division.)

Subsequently, an example of the MP 18,I captured by the British (serial № 214) was forwarded to the Chief Inspector of Small Arms for examination, which was carried out on the 12th of September 1918. A firing test was not possible at this time due to a lack of ammunition, but the CISA compiled a detailed description of the weapon which was published in the minutes of the War Office's Small Arms Committee, referred to as a 'German Machine Pistol firing a .35in pistol cartridge'.

"Report by C.I.S.A., 12.9.18, on German Shoulder Firing Auto Pistol.

Marked Theodor Bergmann Abt. Waffenbau Suhl. M.P.18.I. Every Component numbered 214. Magazine No. 444652.

Description of Pistol. — The pistol is self-loading, inertia operated type, with a specially constructed magazine, holding apparently 32 rounds of ammunition. The bolt is not positively locked at the moment of firing, but depends for retention in closed position on the weight of the bolt and striker, which weigh together 1 lb. 8 ½ oz. plus the weight of the recoil or bolt return spring.
The action and barrel are cased in a tube 19 ⅛ inches long × 1.6 inches in diameter, the front end closed by a perforated collar to position the barrel, and the front portion of the tube is perforated with 8 rows of 8 holes .4 inch in diameter for cooling purposes; the middle of the tube is covered by a casing for strength and to carry the magazine way; lugs on the underside are fitted, which enable to the tube to pivot for stripping for cleaning or removal of bolt, &c.
The magazine way is at the left of the pistol, and fired cases are ejected at the right side through a hole in the tube and magazine casing.
The pistol is fitted with a stock 22 inches long similar to the German rifle, but fuller at the front end, and grooved for gripping purposes, and is fitted with a sling fixed to a bracket on the butt and a swivel lug on the barrel casing.
Action of Mechanism. — Assume the pistol with bolt closed. Insert the charged magazine.
Draw back the bolt; the bolt is retained to the rear by the sear engaging in a bent at the rear end of the bolt.
On pressing the trigger, the bolt is released and drived forward by the bolt return spring, the front of the bolt catching the top cartridge from the magazine and sweeping it into the chamber, and the striker fires the cartridge.
The recoil drives back the bolt, extracting the fired case and ejecting to the right, and the bolt is again returned and fires automatically so long as the pressure is retained on the trigger.
On releasing the trigger the above is repeated until the last cartridge is fired, after which the bolt remains closed.
The cartridge is special to this pistol and differs from any known pistol cartridge, the bore being .347 inch being slightly smaller than for the 9mm., .38 inch, or .380 inch bore pistols, which is .356 inch; the cartridge is also shorter and stouter than the .32 cartridge.
The pistol is simple in construction, strong and well made; it is fitted with a front broad barley-corn sight and a backsight giving two ranges estimated at 25 and 50 metres.
Description of the Magazine. — The magazine is not complete; a sleeve acting as a stop when inserting in Pistol is deficient. This has been fitted in this Department.
The magazine where it enters the pistol is of the usual form, but is continued downwards and ends in a circular form; the platform spring is also of an unusual shape, but is assisted by a flat coil spring housed in the magazine bottom. The insertion of the cartridges into the mouth of the magazine depresses the platform spring and the cartridges are driven down and round the housing. There is a lever on the bottom of the magazine by which the strength of the coil spring may be eased and, in fact, completely taken off by turning the lever until a catch drops into a recess in the bottom plate. After fully charging the magazine the catch is released and pressure applied to the cartridges by the spring.
It is assumed that loading would not be difficult; no cartridges being available for testing.
On the bottom of the magazine the figures 12, 17, 22, 27, 32 are marked. These figures show the number of rounds in the magazine, the folding handle of the spring lever (which does not protrude beyond the bottom of the magazine) pointing to the number as it revolves."

A summarised report of the 'German 1918 Pattern Automatic Pistol-Gun' was published by the British General Headquarters on the 7th of October 1918 which not only went into detail on the working of the MP 18,I, but also provided technical illustrations of the weapon.

The French High Command first described the use of machine pistols by the German Army on the 18th of October 1918, when a memo entitled 'Pistolet Automatique 1918 I.' was issued:

"According to the statements of a recently captured officer, the Germans are now making a new automatic pistol, the parts of which are copied from existing weapons. It will have a magazine for 32 cartridges, similar to the magazine of the long pistol. This weapon will be able to fire 125 shots in 30 seconds, and, according to recent tests, will be superior to the light machine gun. It will be shorter and lighter than the '98 rifle and can be easily handled by a single man in any firing position. It will be issued toward the end of October in the ratio of two pistols to each company. The attention of intelligence officers is directed to this weapon, and it is highly important to secure specimens of it at the earliest possible moment."

It is apparent that some of the details described in this memo, in particular the claim of the machine pistol's superiority over the light machine gun, were probably gleaned from a copy of the above German report on the weapon's efficacy during the field testing stage. The French High Command had seemingly not carried out any physical examination of a captured gun at this time, indicating that the number of guns encountered by the French Army as of early October was likely much lower than the British and Canadian Expeditionary Forces. Indeed there is no written confirmation that the French Army had come into contact with the MP 18,I at all by this point.

A translated copy of this memo (reproduced above) was also issued to the American Expeditionary Force. Troops of the AEF 27th and 30th Divisions possibly encountered the MP 18,I in combat during the Battle of the Selle, where it is known to have been used. Similarly, the AEF 91st Division, subordinated to the French 6e armée, was positioned directly opposite the German 39. Infanterie-Division by the war's end. Despite popular depictions of the Meuse-Argonne Offensive (26th September - 11th November 1918) often including German troops armed with MP 18,I machine pistols, none of the German armies engaged against the AEF during this battle (3. Armee, 5. Armee, Armee-Abteilung C) are known to have been issued with the MP 18,I, though a small number of German divisions later transferred from the 17. Armee (including the 3. Marine-Division) possessed machine pistols during the Meuse-Argonne campaign.

The French Army did not issue a technical description of the MP 18,I until the 1st December 1918, after the armistice. A translated copy of this memo was subsequently published by the US Navy's Office of Naval Intelligence on the 15th June 1919. This memo curiously claims that the MP 18,I was also referred to under the designations '08/15' and 'n./A.', a clear confusion in terminology with the MG 08/15 and LMG 15 n./A. light machine guns, the latter also produced by the Bergmann Abteilung Waffenbau. The claim may not be completely without merit, however; an aforementioned account from the Reserve-Infanterie-Regiment Nr. 80 appears to refer to the MP 18,I as the 'M.G.-Pistole 08/15'.

"MACHINE PISTOL— GERMAN.

Source: French Report on Enemy Munitions.

1 December 1918.

This pistol is a light automatic arm which was recently put into service in the German Army and which makes short rafales at small distances possible.
It fires 9 mm. long pistol, Mod. 1908 cartridges, with magazine drum of 32 cartridges and is manufactured by the firm of Bergmann.

The characteristics of this arm are the following:

Caliber — 9 mm. (exactly 8.84).
Total length of arm — 0.82 m.
Weight without drum magazine — 4.250 kg.
Weight with drum magazine empty — 4,930 kg.
Weight with drum magazine full — 5,865 kg.
Number of rounds — 32
These 32 rounds can be fired in 3.5 seconds.
The cartridge weighs 12.35 g., 8 for the ball and 0.37 for the powder.
It is known that this long pistol is also called Mod. 08/15 pistol and also n/.A new patterns.
This pistol is operated by the recoil and is air cooled.
It is fed by a drum magazine of 32 cartridges, which is the same as that in use for the Mod. 1908 long pistol. This drum is attached to the left side of the arm at the height of the ejection hole in the right side.
The barrel is 20 cm. long and is protected by a casing, in which a number of round holes are pierced, in order to permit the free circulation of the air.
The sight is graduated for fire at 100 to 200 m.
The arm properly so called is mounted on hinges on a wooden stock provided with a butt, with shoulder strap, an arrangement which in its ensemble recalls that of the ordinary hunting rifles."

The Small Arms Committee in Britain, meanwhile, inquired about the possibility of developing a weapon similar to the MP 18,I machine pistol, with the Director of Staff Duties (DSD) outlining a general specification that such a weapon, should it be considered in British service, could take the form of an "automatic pistol which will give reasonable accuracy, with a holster-butt, up to 500 yards". On the 16th July 1919 the Director of Artillery wrote to the DSD inquiring as to whether the General Headquarters was interested in the proposal. A response from the DSD came five days later on the 21st July, and offered the final word on the MP 18,I in British service and gave a rather dismissive opinion of the machine pistol as a class of weapon:

"A really penetrating bullet is necessary to ensure to ensure that the enemy's problems in regard to protection shall remain difficult, to prevent the successful use of body armour, to force the enemy to keep thick heavy armour on his tanks, etc. A heavy high velocity bullet of small calibre (in fact a penetrating bullet) is also required to obtain a flat trajectory; this is necessary to increase danger space and minimise the importance of errors in range. It follows, therefore, that no weapon of the pistol nature can replace the rifle as the infantry's main arm. Its issue will accordingly be limited to those who for some reason or another cannot carry a rifle. This will give pistols a footing in the Army and a chance, if they show themselves worth it, of issue on a larger scale. No "pistol gun" resembling this particular German weapon is required therefore in the British Army, since it is apparently designed as a substitute for rifles and auto rifles, and this violates the principles already stated in this minute."

Production and acceptance numbers

For a more detailed study into this subject, refer to 'Hugo Schmeisser’s Bergmann Sub-machine Guns: M.P.18,I to M.P.18,IV & the SIG Bergmann M.P.' by Hans-Christian Vortisch (Armax Vol. IX No. 1).

The number of MP 18,I machine pistols produced, accepted, and delivered into service during the First World War has long been a source of controversy owing to the lack of known records on the subject. The number of MP 18,I machine pistols produced in total is thought to be just over 37,000; however, it is all but certain that the number of guns which actually came into German infantry use during the war represents only a small fraction of this number.

Based on the records of Heeresgruppe Kronprinz Rupprecht, it can only be said with any certainty that machine pistols assigned to thirteen divisions of the 17. Armee, the 119. Infanterie-Division, and the Sturmbataillon Nr. 8 - accounting for around 1,160 guns in total - verifiably reached their intended recipients at the front.

Further inferences concerning of the number of weapons that saw active combat use can be made from the range of serial numbers observed on surviving trophy guns captured from the front by British, Canadian, and Australian forces. The known examples that trace their provenance to Allied actions on the front typically bear very low serial numbers in the sub-1,000 range, suggesting that the quantities of MP 18,I machine pistols which Allied troops encountered during fighting in late 1918 numbered in the hundreds or low thousands rather than in the tens of thousands.

The most definitive contemporary comment on the number of guns accepted into service (albeit not necessarily issued before the armistice) comes Generalmajor Ernst von Wrisberg, who stated in his 1922 memoir Erinnerungen an Die Kriegsjahre Im Königlich Preussischen Kriegsministerium that 17,000 guns had been accepted into service by October 1918. This seems an accurate estimation as from the physical examination of existing guns, as one of the last known examples bearing a wartime military acceptance stamp is serial № 17,677.

Hans-Christian Vortisch quotes figures from a report compiled in 1918 by the Waffen- und Munitionsbeschaffungsamt ('Arms & Ammunition Procurement Office'), which stated that 96 guns had been completed by May; 1,958 by late June; and 12,500 by early October. Based on these figures, Vortisch estimates that the Bergmann Waffenbau Abteilung achieved a weekly production rate of around 875 units during the war, with around 17,750 guns completed by the time of the armistice in November. Vortisch's calculation is consistent with Generalmajor Wrisberg's figure of c. 17,000 guns completed by October 1918. It is interesting to note that a supply of around 18,000 guns would have been almost exactly sufficient to supply the entire German Army of 1918 (251 divisions) under the reduced distribution rate of 72 guns per division. It is therefore possible that the Preuß. KM had accurately projected by mid-1918 that only around 20,000 units would be completed by the end of the year, and reorganised the size of the M.P.-Trupp accordingly to maintain logistical consistency across the entire Army, which could not have been achieved under the initial distribution rate of 216 guns per division (this would have demanded a supply of over 50,000 guns, consistent with Ludendorff's early projection in March 1918).

These wartime production figures and estimates do not account for the many examples of the MP 18,I machine pistol which bear serial numbers greatly in excess of № 17,000; the serial range observed on surviving guns reaches as high as № 37,025. The overwhelming majority of guns bearing serials higher than № 17,677 do not possess military acceptance stamps and it is therefore likely that these guns were produced or assembled after the end of the war using components manufactured at subcontracted firms, on behalf of German paramilitary and police clients (see Post-war use of the MP 18,I). Vortisch notes three exceptions to this rule; serials № 18,477, № 27,145, and № 31,074. He reasonably speculates these receivers were manufactured and marked with acceptance stamps during the war, but not assembled and serialised until the interwar period.

A very small subsection of MP 18,I machine pistols bearing serials beyond № 50,000 are known to exist. Since there are no known guns at all that bear serials within the 37,026 - 49,999 range, it must be assumed that serial production of the MP 18,I never actually reached 50,000 units, and that guns bearing serials higher than 50,000 must have been manufactured as part of a separate but concurrent production run whose serials were deliberately marked up to make allowance for the full completion of the main military order (indeed, none of the № 50,000+ guns bear either military or police acceptance stamps). The purpose of these guns is currently unknown, though a credible theory is that they may have been intended as trial samples for potential export to Germany's allies Austria-Hungary and the Ottoman Empire. The presence of a twin trigger group on № 50,008, the same type as seen on the early prototype serial № 2, lends credence to the idea that these guns were built for demonstration purposes, as this experimental feature is unlikely to have been present on a weapon intended for military service.

Post-war use of the MP 18,I

Regulation of machine pistols by the Treaty of Versailles

Though it is commonly claimed that the victorious Allied powers immediately banned the use of the MP 18,I by the German Army in the Treaty of Versailles, in fact there are no references to machine pistols whatsoever in the treaty. Machine pistols or submachine guns were not a familiar concept at this time to the British, French, and American military authorities, and only the Italians - who were probably unaware of or unconcerned by the existence of the MP 18,I - recognised the machine pistol as an extant class of small arms. Therefore in the original terms of the treaty, no provisions were made by the Allies whatsoever concerning the restriction of machine pistols within German service.

The restrictions on the number of small arms that the post-war German Army was permitted to possess was stated in the original text of the Treaty of Versailles as:

Material	Infantry Division (1)	For 7 Infantry Divisions (2)	Cavalry Division (3)	For 3 Cavalry Divisions (4)	2 Army Corps Headquarters Staff (5)	Total of columns 2, 4, and 5 (6)
Rifles	12,000	84,000	0	0	This establishment must be drawn from the increased armaments of the divisional infantry.	84,000
Carbines	0	0	6,000	18,000	Per above	18,000
Heavy machine guns	108	756	12	36	Per above	792
Light machine guns	162	1,134	0	0	Per above	1,134

Later reproductions of the terms of the treaty included a clause stating that 'Automatic Rifles' were to be counted as Light Machine Guns, though there was no elaboration on what constituted an automatic rifle, or whether machine pistols fell under this category. In any case, neither the Interalliierte Militär-Kontroll-Kommission (I.M.K.K.; 'Inter-Allied Commission of Control') - the Allied body responsible for enforcing the terms of the Treaty - nor the German Army itself initially treated machine pistols as automatic rifles.