MP 40

The MP 38 and MP 40 (MP designates Maschinenpistole, literally "Machine Pistol") is a submachine gun developed in Nazi Germany and used extensively by paratroopers, tank crews, platoon and squad leaders, and other troops during World War II. The MP 40 was characterized by its low rate of fire and low recoil.

Development
The MP 40 was descended from its predecessor, the MP 38, which was in turn based on the MP 36, a prototype made of machined steel. The MP 36 was developed independently by Erma Werke's Berthold Geipel with funding from the German Army. It took design elements from Heinrich Vollmer's VPM 1930 and EMP. Vollmer then worked on Berthold Geipel's MP 36 and in 1938 submitted a prototype to answer a request from the German Armament services for a new submachine gun, which was adopted as MP 38. The MP 38 was a simplification of the MP 36, and the MP 40 was a further simplification of the MP 38, with certain cost-saving alterations, notably in the more extensive use of stamped rather than machined parts.

Other changes resulted from experiences with the several thousand MP 38s in service since 1939, which had been used in action during the invasion of Poland. The changes were incorporated into an intermediate version, the MP 38/40, and then used in the initial MP 40 production version. Just over 1 million would be made of all versions in the course of the war.

The MP 40 was often called the "Schmeisser" by the Allies, after weapons designer Hugo Schmeisser. Schmeisser had designed the MP 18, which was the first mass-produced submachine gun, and saw extensive service at the end of the First World War. He did not, however, design the MP 40, although he held a patent on the magazine. He later designed the MP 41, which was an MP 40 with a wooden rifle stock and a selector, identical to those found on the earlier MP 28 submachine gun. The MP 41 was not introduced as a service weapon with the German Army, but saw limited use with some SS and police units. They were also exported to Germany's ally, Romania. The MP 41's production run was brief, as Erma filed a successful patent infringement lawsuit against Schmeisser's employer, Haenel.

Despite the impression given by popular culture, particularly in war films, MP 40s were generally issued only to paratroopers and platoon and squad leaders; the majority of German soldiers carried Karabiner 98k rifles. However, later experience with Soviet tactics - where entire units armed with submachine guns outgunned their German counterparts in short range urban combat - caused a shift in tactics, and by the end of the war the MP 40 and its derivatives were being issued to entire assault platoons on a limited basis.

There were never enough MP 40s to go around, because raw material and labor costs made it expensive to produce alongside the Kar98 rifles. Starting in 1943, the German army moved to replace both the Kar-98 rifle and MP 40 with the new MP 43/44 assault rifle, also known later as the StG 44.

Design
Both MP 38 and MP 40 submachine guns are open-bolt, blowback-operated automatic arms. Fully automatic fire was the only setting, but the relatively low rate of fire allowed for single shots with controlled trigger pulls. The bolt features a telescoping return spring guide which serves as a pneumatic recoil buffer. The cocking handle was permanently attached to the bolt on early MP 38s, but on late production MP 38s and MP 40s, the bolt handle was made as a separate part. It also served as a safety by pushing the head of handle into a separate notch above the main opening, which locked the bolt either in the cocked or forward position. The absence of this feature on early MP 38s resulted in field expedients such as leather harnesses with a small loop, used to hold the bolt in forward position.

The receiver was originally machined steel but this was a time-consuming and expensive process. This prompted the development of a simpler version that used stamped steel and electro-spot welding as much as possible. The MP 38 also features longitudinal grooving on the receiver and bolt, as well as a circular opening on the magazine housing. These features were suppressed on the M38/40 and MP 40.

One idiosyncratic and visible feature on most MP 38 and MP 40 submachine guns was an aluminum, steel, or bakelite resting bar or support under the barrel which was used to steady the weapon when firing over the side of open top armored personnel carriers such as the Sdkfz 251 half-track. A handguard was located between the magazine housing and pistol grip and was made of synthetic material derived from bakelite. The barrel lacked any form of insulation, which often resulted in burns for the supporting hand if it strayed. It also had a compact folding metal stock, the first for a submachine gun, resulting in a shorter weapon when folded, but it was at times insufficiently durable for hard use in combat.

Although the MP 40 was generally reliable, a major weak point was its 32-round magazine. Unlike the Thompson's double-column, dual-feed magazine, the MP 38 and MP 40 used a double-column, single-feed design. The single-feed resulted in increased friction against the remaining cartridges moving upwards towards the feed lips, occasionally resulting in a failure to feed; the problem was exacerbated by the presence of dirt or dust. Another problem was that the magazine was also sometimes misused as a handhold, which could cause the weapon to malfunction when hand pressure on the magazine body caused the magazine lips to move out of the line of feed, since the magazine well did not keep the magazine firmly locked. German soldiers were trained to grasp either the intended handhold on the underside of the weapon or the magazine housing with the supporting hand to avoid feed malfunctions.

Copies and Post-War Usage
After the end of the Second World War, many MP40's that were captured by the allies were redistributed as surplus weapons to many developing countries, paramilitary and irregular forces where they ended up being used in battlefields such as Greece, Israel, and Vietnam.

The MP 38 or MP 40 was also a pattern for diverse submachine guns such as:


 * The Spanish company Star Bonifacio Echeverria, S.A. produced the Star Modelo Z-45, a variant of the MP 40. Produced in 9x23mm Largo, the Z-45 is a selective-fire submachine gun, equipped with either a wooden or a folding metal buttstock, and wooden handguards. Its magazine was a copy of the MP 40, and held 30 rounds. It served in Spain, Cuba, Chile, Portugal and Saudi Arabia and was used for the first time in combat in the battle of Sidi Ifni.


 * The Norwegian Army used the MP 40 from 1945 until about 1970 and other parts of the Norwegian armed forces, such as the Norwegian Home Guard, still issued the MP 40 up into the early 1990s.


 * Some MP 40s were in use by the Kosovo Liberation Army in the Kosovo War in 1999.


 * Two MP 40s were used by the LAPD SWAT team during the famous May 1974 shootout with members of the terrorist Symbionese Liberation Army.

Variants and Development

 * MP 40/I — main production version


 * MP 40/II — experiment with two side by side 32-round magazines. The MP 40/II was tested in 1942. This version of the MP 40 has a two-magazine receiver that slides horizontally to use the additional magazine when the first becomes depleted. This design was intended to counter the superior firepower of the Russian PPSh-41, but made the weapon heavy and unbalanced in the field, and did not work well. However, by 1943 the Soviets shifted the production of PPSh-41 drums to 35 round magazines to combat malfunctions.


 * MP 41 — A variant designed by Louis Schmeisser for the Haenel Company, which featured the receiver, operating mechanism, and magazine housing of the MP 40 and the stock, trigger and fire selector similar to the MP 28.


 * Many countries involved in World War II developed submachine guns which had a similar features to the MP 40 (with a folding stock, magazine as a front handgrip, and production techniques). The most famous examples are the Russian PPS-43 and the American M3 submachine gun. Most derivative designs also copied the troublesome magazine design as well.


 * BD38 — a new semi-automatic reproduction of the MP 38 submachinegun.

Specifications
Type Submachine gun

Place of origin Nazi Germany

In service 1939–1945

Wars World War II, Cold War (Limited)

Designer Heinrich Vollmer

Designed 1938

Manufacturer Erma Werke

Produced 1940–1945

Number built Approx. 1 million

Variants MP 36, MP 38, MP 40, MP 40/1, MP 41

Weight 4 kg (8.82 lb)

Length 833 mm (32.8 in) stock extended / 630 mm (24.8 in) stock folded

Barrel length 251 mm (9.9 in)

Cartridge 9x19mm Parabellum

Action Straight blowback, open bolt

Rate of fire 550 rounds/min

Muzzle velocity ~380 m/s (1,247 ft/s)

Effective range 100 m

Maximum range 200 m

Feed system 32-round detachable box magazine

Sights Hooded front blade, fixed and flip-up U-notch rear