|Full text name||EMP.35 Erma|
|Caliber cartridge||9mm Luger - 9x19 Luger / Parabellum|
|Overall length, mm||950|
|Length, folded, mm||892|
|Barrel length, mm||250/308|
|Weight empty, kg||4.1|
|Magazine capacity, rounds||32|
|Cyclic rate of fire, rounds/min||450-500|
Heinrich Vollmer, an arms designer from Germany, designed his first submachine gun in 1925. His first weapon looked much like the Bergmann / Schmeisser MP-18/I,but with certain differences such as vertical foregrip and a small, drum-type magazine which was attached below the receiver and held 25 rounds of 9 mm pistol ammunition. He gradually improved his weapon up until 1928 or 1929, when he made first commercial sales of the new submachine gun, which was offered in a variety of calibers, including 7,65×22 Luger, 7,63×25 Mauser, 9×19 Luger and 9×25 Mauser Export.
In 1930, Vollmer introduced an improved design, with side-feed using boxmagazines and patented telescoped return spring guide, later used in famous MP-38 and MP-40 submachine guns. Since the Vollmer himself has not enough financial capabilities to produce this gun on commercial basis, in 1931 he sold the manufacturing rights to German Erfurter Maschinen fabrik company,usually known under its trade mark Erma.
Erma produced Vollmer design in a variety of models under one common name EMP (Erma Maschinen Pistole – Erma machine pistol). These weapons differed in length of the barrel, type of sights, safety arrangements and availability of accessories,but general layout and features were the same. EMP submachine guns were sold to France, Spain and several South American countries. Germans mostly issued ErmaEMP submachine guns to police and Waffen SS troops.
Erma EMP submachine gun is blowback operated, selective-fired weapon which fires from open bolt. It uses characteristic bolt system with telescoped tubular guide for return spring. The standard safety consisted of a hook-shaped notch in the receiver, which was used to engage and lock the bolt in cocked position. Additionally, on some EMP weapons, a manual safety was installed on the left side of receiver, behind the magazine housing. The fire mode selector was located on the right side of the stock, above the trigger guard. The feed was from the left side, using double-row box magazines. The magazine housing was slightly canted forward to improve feeding. Ejection was to the right. The stock with semi-pistol grip was made from wood; standard versions had additional front grip under the stock, but Erma also produced version of EMP without this fore grip.Sights also varied – Erma produced EMP submachine guns with two-position flip-up or with tangent rear sights.
EMP also had one more unusual design feature – a disassembly catch that was located at the rear of the trigger guard. There was nothing wrong with it – until shooter hit it with his fingers during combat, which resulted in instant self-disassembly of the weapon – a very unwelcome event for any fighting soldier.