MP18
Encyclopedia
The MP18.1 manufactured by Theodor Bergmann
Waffenbau Abteilung was the first practical submachine gun
used in combat. It was introduced into service in 1918 by the German Army
during World War I
as the primary weapon of the Stosstruppen, assault groups specialized in trench combat
. Although MP18 production ended in the 1920s, its design formed the basis of most submachine guns manufactured between 1920 and 1960.
The firepower of this new class of weapons made such an impression on the Allies that the Treaty of Versailles
specifically banned further study and manufacture of such light automatic firearms by Germany.
What became known as the "submachine gun" had its genesis in the early 20th Century and developed around the concepts of infiltration and fire and movement, specifically for the task of clearing trenches of enemy soldiers, an environment within which engagements were unlikely to occur beyond a range of a few feet.
In 1915, the German Rifle Testing Commission at Spandau
decided to develop a new weapon for trench warfare. An attempt to modify existing semi-automatic pistols, specifically the Luger
and C96 Mauser
failed, as accurate aimed fire in full automatic mode was impossible due to their light weight and high rate of fire of 1,200 rounds per minute. The Commission determined that a completely new kind of weapon was needed. Hugo Schmeisser
, working for the Bergmann Waffenfabrik was part of a team composed of Theodor Bergmann
, Louis Schmeisser and a few other technicians. They designed a new type of weapon to fulfill the requirements, which was designated the Maschinenpistole 18/I. It is not clear what the "I" designation is intended to indicate, although its successor, the MP28, was designated the Maschinenpistole 28/II.
Full scale production did not begin until early 1918. Though technically not the world's first submachine gun, being beaten by the Italian Villar-Perosa
of 1915, in modern usage of the term the MP18 is considered the world's first submachine gun
since the Villar Perosa had been designed to be used as a light machine gun
on aircraft before it was adapted to infantry use.
, manufacture continued in secret into the early 1920s, as the final production total (again, based upon observed serial numbers) ended at around 35,000.
The MP18 proved to be an excellent weapon. Its concept was well proven in trench fights. Its basic design directly influenced later submachine gun designs and showed its superiority vs the regular infantry rifle in urban combat and mobile warfare as well as in guerrilla warfare. In 1919 during the German revolutionary period, MP 18 were used successfully in house to house fights to regain control of a city in Berlin and Munich in what was more police type counter insurgency than a military operation.
All the limited conflicts between 1920 and 1940 saw an increasing use of this new class of weapons, first in South America during the Chaco War
, then in Europe during the Spanish Civil War
, and in China during the Japanese invasion where its use by well trained Chinese troops was costly for the invaders as in the battle of Shanghai
, where fierce street fights prefigured World War II
urban combat of Stalingrad
, Warsaw
, Vienna
and Berlin
.
The MP18 continued in use with German police forces after the end of the war. It was widely used in combat by the Freikorps
Von Epp against the Spartacus League in Bavaria and by some other Freikorps in Berlin where its efficiency in urban combat was demonstrated. Since the Treaty of Versailles prohibited the use and manufacture of pistols with a barrel over four inches (102 mm) and/or a magazine capacity over eight rounds, all Trommel Magazines TM 08 were destroyed.
Since the Treaty allowed the Weimar Republic
to keep a small quantity of submachine guns for police use, a few hundred MP18.1 were modified to accept Schmeisser's original 20 round magazine design. This modification, conducted by Haenel Waffenfabrik, required removal of the existing magazine well collar, and replacement with a different one. These weapons were overstamped with the date "1920" on receiver and magazine well to show they were legitimate weapons owned by the Weimar Republic and not war bringbacks or clandestine weapons.
Bergmann sold the license of the MP18. 1 to SIG
Switzerland
; the Swiss made model was known as SIG Bergmann 1920. It existed in .30 Luger, 9mm Parabellum and 7.63 mm Mauser. The Bergmann MP18.1 represents a milestone both in terms of armament technology and warfare tactics. It opened the way for a whole new class of weapons and triggered the research for lighter automatic firearms to be used by mobile troops. Its first direct competitors did not see service in World War I, but most of them saw use in all the limited conflicts taking place in the inter-war period.
The Chinese produced a modified MP18 in Tsing Tao with the assistance of Heinrich Vollmer
. The French, despite being moderately interested by this class of armament because they had designed and introduced in service many semi-automatic and automatic weapons, immediately launched studies based on captured MP 18s. The design of the STA 1922 was adopted and the MAS 1924 entered service and was used in colonial war. The French MAS 35 and MAS 38 derived from one of the many prototypes of the immediate post war.
The MP28 was produced by Haenel under the supervision of Hugo Schmeisser, it was copied by the Second Spanish Republic
under the codename Naranjero. The Naranjero was chambered in 9mm Largo
.
The Austrian Steyr MP34
was created by a team of technicians led by Louis Stange who designed a submachine gun for Rheinmetall in 1919 and used Bergmann's MG15 to design the MG 30. The SIG Bergmann 1920 was used by Finland and Estonia, it was the inspiration for the Estonian Tallinn 1923 and the Finnish Suomi model 31, which in turn inspired Degtyarev for his PPD 34.
Emil Bergmann, Theodor Bergmann's son designed the MP32 that evolved into the MP34 as adopted by Denmark before to receive the MP35
name when adopted by nascent Wehrmacht
in 1935. This SMG is often mistaken with the Mitraillette 34, a MP28 made in Belgium by Pieper Bayard, former Bergmann licensed manufacturer or with the MP34 made by Steyr. It is easy to identify the Bergmann MP 32/34/35 or its final version 35/1 since the cocking lever works exactly like a rifle bolt.
In 1940, with a pressing need for individual automatic weapons, the British copied the MP28 and developed the Lanchester submachine gun for the Royal Navy
. Solidly built with the use of brass
for the magazine well, and a bayonet mount, it entered service in 1940. The magazine and the bolt of the MP28 could be used in the Lanchester.
The OVP 1918, an offspring of Revelli's Villar Perosa 1915, inspired Heinrich Vollmer for his telescopic bolt used in the VPM 1930, EMP, MP38, MP40 and MP41. The MP18 remained in limited service with the German armed forces during the Second World War, specifically with the Sicherheitsdienst
, later eastern foreign divisions of the Waffen SS and also with Kriegsmarine
coastal artillery units.
tube was very thick (~3 mm), compared with later World War II
submachine guns with half that thickness or less, such as the Sten gun or MP40
.
Though Schmeisser designed a conventional 20 round capacity "box" magazine
for the weapon, the Testing Commission, for practical reasons, insisted that the MP18 be adapted to use the 32 round TM 08 Luger "snail" drum magazines that was widely used with the long barreled version of the P 08 pistol known as Artillery model.
The MP-18 design had a drawback common to all open-bolt designs: That of accidental discharge. If the buttstock of a loaded gun was given a hard knock while the bolt was fully forward, the gun could accidentally fire because of the bolt overcoming the action spring resistance and moving rearward enough to pick up a round, chamber it and fire. Soldiers liked to leave the bolt of their firearm in the closed or forward position so dirt and debris would not enter into the barrel and chamber. This 'Bolt-closure' practice acted as a dust cover for the weapons chamber, preventing a malfunction
from occurring because of the presence of foreign debris.
The German police asked for an external safety on its MP18 and a universal bolt locking safety was added on all the submachine guns used by the police. Later sub-machine gun designs like the Sten or the MP40 were modified to allow the cocking handle to be pushed inwards to lock the closed bolt to the tubular receiver casing. This design change prevented accidental discharges when the bolt was left forward and a loaded magazine was inserted.
The original MP18.1 was designed to use the snail drum magazine of the Luger Artillery model pistol. This rotary design type of magazine holds 32 rounds of 9 mm Parabellum, the user having to load the magazine with a proprietary loading tool. A special sleeve was required when the snail drum was used on the MP18 to stop the snail drum from being inserted too far in the magazine well.
After 1920, the MP18 was modified to use a straight magazine similar to those used in the later developed MP40 submachine gun. The MP18 could only fire in the fully automatic mode. Its successor, the MP28/2, received a modified mechanism with a selector for single shot or fully automatic fire.
Britain directly copied the MP28 at the beginning of World War II
. The result was the Lanchester submachine gun, which saw service with the Royal Navy
. The British Sten
used the side-mounted magazine configuration and a simplified version of the open bolt firing operating system of the MP28.
Soviet Union made a similar use of MP 18 design in their PPD-40
sub machine gun in 1934. Further development of PPD-40 lead to simplified and mass-produced PPSh-41
.
Theodor Bergmann
Theodor Bergmann was a German businessman and industrialist best remembered for the various revolutionary firearms his companies released. Like many entrepreneurs of the era, his activity was centered on bicycles and the nascent automobile...
Waffenbau Abteilung was the first practical submachine gun
Submachine gun
A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...
used in combat. It was introduced into service in 1918 by the German Army
German Army
The German Army is the land component of the armed forces of the Federal Republic of Germany. Following the disbanding of the Wehrmacht after World War II, it was re-established in 1955 as the Bundesheer, part of the newly formed West German Bundeswehr along with the Navy and the Air Force...
during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
as the primary weapon of the Stosstruppen, assault groups specialized in trench combat
Trench warfare
Trench warfare is a form of occupied fighting lines, consisting largely of trenches, in which troops are largely immune to the enemy's small arms fire and are substantially sheltered from artillery...
. Although MP18 production ended in the 1920s, its design formed the basis of most submachine guns manufactured between 1920 and 1960.
The firepower of this new class of weapons made such an impression on the Allies that the Treaty of Versailles
Treaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...
specifically banned further study and manufacture of such light automatic firearms by Germany.
History
In 1915, the German Rifle Testing Commission at Spandau
Spandau
Spandau is the fifth of the twelve boroughs of Berlin. It is the fourth largest and westernmost borough, situated at the confluence of the Havel and Spree rivers and along the western bank of the Havel, but the least populated.-Overview:...
decided to develop a new weapon for trench warfare. An attempt to modify existing semi-automatic pistols, specifically the Luger
Luger pistol
The Pistole Parabellum 1908 or Parabellum-Pistole , popularly known as the Luger, is a toggle-locked recoil-operated semi-automatic pistol. The design was patented by Georg J...
and C96 Mauser
Mauser C96
The Mauser C96 is a semi-automatic pistol that was originally produced by German arms manufacturer Mauser from 1896 to 1937...
failed, as accurate aimed fire in full automatic mode was impossible due to their light weight and high rate of fire of 1,200 rounds per minute. The Commission determined that a completely new kind of weapon was needed. Hugo Schmeisser
Hugo Schmeisser
Hugo Schmeisser was a German developer of infantry weapons in the 20th century.Schmeisser was born in Jena, Saxe-Weimar. His father, Louis Schmeisser , was one of the best-known weapons designers in Europe...
, working for the Bergmann Waffenfabrik was part of a team composed of Theodor Bergmann
Theodor Bergmann
Theodor Bergmann was a German businessman and industrialist best remembered for the various revolutionary firearms his companies released. Like many entrepreneurs of the era, his activity was centered on bicycles and the nascent automobile...
, Louis Schmeisser and a few other technicians. They designed a new type of weapon to fulfill the requirements, which was designated the Maschinenpistole 18/I. It is not clear what the "I" designation is intended to indicate, although its successor, the MP28, was designated the Maschinenpistole 28/II.
Full scale production did not begin until early 1918. Though technically not the world's first submachine gun, being beaten by the Italian Villar-Perosa
Villar-Perosa aircraft submachine gun
The Villar-Perosa aircraft submachine gun was an Italian double barreled light machine gun designed by Bethel Abiel Revelli, a Major in the Italian Army in 1914. The weapon fired pistol calibre 9 mm Glisenti ammunition, a reduced-power version of the famous 9 mm Para, at the extremely high rate of...
of 1915, in modern usage of the term the MP18 is considered the world's first submachine gun
Submachine gun
A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...
since the Villar Perosa had been designed to be used as a light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
on aircraft before it was adapted to infantry use.
Service history
The MP18 primarily served in final stages of World War I in 1918, especially in the so-called Kaiserschlacht offensive. At least 5,000 MP18.1 were built and used during World War I, based upon observed serial number ranges of captured weapons; however, it is possible that up to 10,000 were built for the war. Though production was outlawed by the Treaty of VersaillesTreaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...
, manufacture continued in secret into the early 1920s, as the final production total (again, based upon observed serial numbers) ended at around 35,000.
The MP18 proved to be an excellent weapon. Its concept was well proven in trench fights. Its basic design directly influenced later submachine gun designs and showed its superiority vs the regular infantry rifle in urban combat and mobile warfare as well as in guerrilla warfare. In 1919 during the German revolutionary period, MP 18 were used successfully in house to house fights to regain control of a city in Berlin and Munich in what was more police type counter insurgency than a military operation.
All the limited conflicts between 1920 and 1940 saw an increasing use of this new class of weapons, first in South America during the Chaco War
Chaco War
The Chaco War was fought between Bolivia and Paraguay over control of the northern part of the Gran Chaco region of South America, which was incorrectly thought to be rich in oil. It is also referred to as La Guerra de la Sed in literary circles for being fought in the semi-arid Chaco...
, then in Europe during the Spanish Civil War
Spanish Civil War
The Spanish Civil WarAlso known as The Crusade among Nationalists, the Fourth Carlist War among Carlists, and The Rebellion or Uprising among Republicans. was a major conflict fought in Spain from 17 July 1936 to 1 April 1939...
, and in China during the Japanese invasion where its use by well trained Chinese troops was costly for the invaders as in the battle of Shanghai
Battle of Shanghai
The Battle of Shanghai, known in Chinese as Battle of Songhu, was the first of the twenty-two major engagements fought between the National Revolutionary Army of the Republic of China and the Imperial Japanese Army of the Empire of Japan during the Second Sino-Japanese War...
, where fierce street fights prefigured World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
urban combat of Stalingrad
Battle of Stalingrad
The Battle of Stalingrad was a major battle of World War II in which Nazi Germany and its allies fought the Soviet Union for control of the city of Stalingrad in southwestern Russia. The battle took place between 23 August 1942 and 2 February 1943...
, Warsaw
Warsaw Uprising
The Warsaw Uprising was a major World War II operation by the Polish resistance Home Army , to liberate Warsaw from Nazi Germany. The rebellion was timed to coincide with the Soviet Union's Red Army approaching the eastern suburbs of the city and the retreat of German forces...
, Vienna
Vienna Offensive
The Vienna Offensive was launched by the Soviet 3rd Ukrainian Front in order to capture Vienna, Austria. The offensive lasted from 2–13 April 1945...
and Berlin
Battle of Berlin
The Battle of Berlin, designated the Berlin Strategic Offensive Operation by the Soviet Union, was the final major offensive of the European Theatre of World War II....
.
The MP18 continued in use with German police forces after the end of the war. It was widely used in combat by the Freikorps
Freikorps
Freikorps are German volunteer military or paramilitary units. The term was originally applied to voluntary armies formed in German lands from the middle of the 18th century onwards. Between World War I and World War II the term was also used for the paramilitary organizations that arose during...
Von Epp against the Spartacus League in Bavaria and by some other Freikorps in Berlin where its efficiency in urban combat was demonstrated. Since the Treaty of Versailles prohibited the use and manufacture of pistols with a barrel over four inches (102 mm) and/or a magazine capacity over eight rounds, all Trommel Magazines TM 08 were destroyed.
Weimar Republic
The Weimar Republic is the name given by historians to the parliamentary republic established in 1919 in Germany to replace the imperial form of government...
to keep a small quantity of submachine guns for police use, a few hundred MP18.1 were modified to accept Schmeisser's original 20 round magazine design. This modification, conducted by Haenel Waffenfabrik, required removal of the existing magazine well collar, and replacement with a different one. These weapons were overstamped with the date "1920" on receiver and magazine well to show they were legitimate weapons owned by the Weimar Republic and not war bringbacks or clandestine weapons.
Bergmann sold the license of the MP18. 1 to SIG
Schweizerische Industrie Gesellschaft
Schweizerische Industrie Gesellschaft , or SIG, is the former name of SIG Holding AG, a Swiss company that has been active in various businesses during its more than 150 years of operation. Since the year 2000 the Society has undergone strategic refocus, concentrating on its core compentence in...
Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
; the Swiss made model was known as SIG Bergmann 1920. It existed in .30 Luger, 9mm Parabellum and 7.63 mm Mauser. The Bergmann MP18.1 represents a milestone both in terms of armament technology and warfare tactics. It opened the way for a whole new class of weapons and triggered the research for lighter automatic firearms to be used by mobile troops. Its first direct competitors did not see service in World War I, but most of them saw use in all the limited conflicts taking place in the inter-war period.
Evolution
Heinrich Vollmer
Heinrich Vollmer was a well-known weapon designer of Europe.The chief designer Heinrich Vollmer, working for Erma Werke in Erfurt, used Bertold Geipel's MP36 to develop one of the most famous German submachine guns of the Second World War, MP38/MP40...
. The French, despite being moderately interested by this class of armament because they had designed and introduced in service many semi-automatic and automatic weapons, immediately launched studies based on captured MP 18s. The design of the STA 1922 was adopted and the MAS 1924 entered service and was used in colonial war. The French MAS 35 and MAS 38 derived from one of the many prototypes of the immediate post war.
The MP28 was produced by Haenel under the supervision of Hugo Schmeisser, it was copied by the Second Spanish Republic
Second Spanish Republic
The Second Spanish Republic was the government of Spain between April 14 1931, and its destruction by a military rebellion, led by General Francisco Franco....
under the codename Naranjero. The Naranjero was chambered in 9mm Largo
9 mm Largo
The 9×23mm Largo centerfire pistol cartridge was developed in 1901 for the Bergmann Mars pistol. The round was considered powerful for the day, producing a muzzle energy of between 330 and 430 foot-pounds depending on the loading...
.
The Austrian Steyr MP34
MP34
The MP34 is a submachine gun that was manufactured by Waffenfabrik Steyr and used by the Austrian police and subsequently by units of the German army, including the Waffen SS, in World War II...
was created by a team of technicians led by Louis Stange who designed a submachine gun for Rheinmetall in 1919 and used Bergmann's MG15 to design the MG 30. The SIG Bergmann 1920 was used by Finland and Estonia, it was the inspiration for the Estonian Tallinn 1923 and the Finnish Suomi model 31, which in turn inspired Degtyarev for his PPD 34.
Emil Bergmann, Theodor Bergmann's son designed the MP32 that evolved into the MP34 as adopted by Denmark before to receive the MP35
MP35
The MP35 was a submachine gun used by the Wehrmacht, Waffen-SS and German police both before and during World War II...
name when adopted by nascent Wehrmacht
Wehrmacht
The Wehrmacht – from , to defend and , the might/power) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer , the Kriegsmarine and the Luftwaffe .-Origin and use of the term:...
in 1935. This SMG is often mistaken with the Mitraillette 34, a MP28 made in Belgium by Pieper Bayard, former Bergmann licensed manufacturer or with the MP34 made by Steyr. It is easy to identify the Bergmann MP 32/34/35 or its final version 35/1 since the cocking lever works exactly like a rifle bolt.
In 1940, with a pressing need for individual automatic weapons, the British copied the MP28 and developed the Lanchester submachine gun for the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
. Solidly built with the use of brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
for the magazine well, and a bayonet mount, it entered service in 1940. The magazine and the bolt of the MP28 could be used in the Lanchester.
The OVP 1918, an offspring of Revelli's Villar Perosa 1915, inspired Heinrich Vollmer for his telescopic bolt used in the VPM 1930, EMP, MP38, MP40 and MP41. The MP18 remained in limited service with the German armed forces during the Second World War, specifically with the Sicherheitsdienst
Sicherheitsdienst
Sicherheitsdienst , full title Sicherheitsdienst des Reichsführers-SS, or SD, was the intelligence agency of the SS and the Nazi Party in Nazi Germany. The organization was the first Nazi Party intelligence organization to be established and was often considered a "sister organization" with the...
, later eastern foreign divisions of the Waffen SS and also with Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...
coastal artillery units.
Design details
A soundly engineered piece of equipment with near commercial grade fittings and finish, the MP18 was a heavy weapon, weighing over 5 kg (11 lb) when fully loaded. The receiverReceiver (firearms)
In firearms terminology, the receiver is the part of a firearm that houses the operating parts. The receiver usually contains the bolt carrier group, trigger group, and magazine port. In most handguns, the receiver, or frame, holds the magazine well or rotary magazine as well as the trigger mechanism...
tube was very thick (~3 mm), compared with later World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
submachine guns with half that thickness or less, such as the Sten gun or MP40
MP40
The MP 38 and MP 40 , often called Schmeisser, were submachine guns developed in Nazi Germany and used extensively by paratroopers, tank crews, platoon and squad leaders, and other troops during World War II.-Development:The MP 40 descended from its predecessor, the MP 38, which was in turn based...
.
Magazine (firearm)
A magazine is an ammunition storage and feeding device within or attached to a repeating firearm. Magazines may be integral to the firearm or removable . The magazine functions by moving the cartridges stored in the magazine into a position where they may be loaded into the chamber by the action...
for the weapon, the Testing Commission, for practical reasons, insisted that the MP18 be adapted to use the 32 round TM 08 Luger "snail" drum magazines that was widely used with the long barreled version of the P 08 pistol known as Artillery model.
The MP-18 design had a drawback common to all open-bolt designs: That of accidental discharge. If the buttstock of a loaded gun was given a hard knock while the bolt was fully forward, the gun could accidentally fire because of the bolt overcoming the action spring resistance and moving rearward enough to pick up a round, chamber it and fire. Soldiers liked to leave the bolt of their firearm in the closed or forward position so dirt and debris would not enter into the barrel and chamber. This 'Bolt-closure' practice acted as a dust cover for the weapons chamber, preventing a malfunction
Firearm malfunction
A firearm malfunction is the partial or complete failure of a firearm to operate as intended. Malfunctions range from temporary and relatively safe situations, such as a casing that didn't eject, to potentially dangerous occurrences that may permanently damage the gun and cause injury or death...
from occurring because of the presence of foreign debris.
The German police asked for an external safety on its MP18 and a universal bolt locking safety was added on all the submachine guns used by the police. Later sub-machine gun designs like the Sten or the MP40 were modified to allow the cocking handle to be pushed inwards to lock the closed bolt to the tubular receiver casing. This design change prevented accidental discharges when the bolt was left forward and a loaded magazine was inserted.
Operation
The original MP18.1 was designed to use the snail drum magazine of the Luger Artillery model pistol. This rotary design type of magazine holds 32 rounds of 9 mm Parabellum, the user having to load the magazine with a proprietary loading tool. A special sleeve was required when the snail drum was used on the MP18 to stop the snail drum from being inserted too far in the magazine well.
After 1920, the MP18 was modified to use a straight magazine similar to those used in the later developed MP40 submachine gun. The MP18 could only fire in the fully automatic mode. Its successor, the MP28/2, received a modified mechanism with a selector for single shot or fully automatic fire.
Britain directly copied the MP28 at the beginning of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The result was the Lanchester submachine gun, which saw service with the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
. The British Sten
Sten
The STEN was a family of British 9 mm submachine guns used extensively by British and Commonwealth forces throughout World War II and the Korean War...
used the side-mounted magazine configuration and a simplified version of the open bolt firing operating system of the MP28.
Soviet Union made a similar use of MP 18 design in their PPD-40
PPD-40
The PPD is a submachine gun originally designed in 1934. The PPD had a conventional wooden stock, fired from an open bolt, and was capable of selective fire....
sub machine gun in 1934. Further development of PPD-40 lead to simplified and mass-produced PPSh-41
PPSh-41
The PPSh-41 was a Soviet submachine gun designed by Georgi Shpagin as an inexpensive, simplified alternative to the PPD-40. Intended for use by minimally-trained conscript soldiers, the PPSh was a magazine-fed selective-fire submachine gun using an open-bolt, blowback action...
.