MP40 Country Germany Type Submachine gun Manufacturer Heinrich Vollmer Introduction 1938 Specifications Weight 4 kg (8.8 lb) Length 833 mm (32.8 in) 630 mm (24.8 in) w/stock folded Barrel length 251 mm (9.9 in) Cartridge 9x19mm Parabellum Action blowback, open bolt Rate of fire 500 rounds/min Muzzle velocity ~380 m/s (1,247 ft/s) Effective range 100 m (110 yd) Maximum range 200 m (220 yd) Feed system 32-round detachable box magazine Sights Hooded blade front, fixed and flip-up U-notch rear

The MP40 (Maschinenpistole 40, literally Machine Pistol 40) is a submachine gun developed in Germany and used extensively by paratroopers and platoon and squad leaders, and other troops during World War II. The MP40 had a relatively low rate of fire and low recoil, which made it more manageable than other contemporary submachine guns.

The MP40 is descended from its predecessor, the MP38. The MP36, a prototype made of machined steel, was developed independently by Erma\'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 MP36 and in 1938 submitted a prototype to answer a request from the German Armament services for a new submachine gun, which was adopted as MP38. The MP38 was a simplification of the MP36, as the MP40 was a further simplification of the MP38, with certain cost-saving alterations, notably in the use of more pressed rather than machined parts.

Other changes resulted from experiences with the several thousand MP38s in service since 1939, used during the invasion of Poland. The changes were incorporated into an intermediate version, the MP38/40, and then used in the initial MP40 production version. Just over 1 million would be made of all versions in the course of the war.

The MP40 was often called the Schmeisser by the Allies, after weapons designer Hugo Schmeisser. Hugo Schmeisser himself did not design the MP40 but held a patent on the magazine.