The MP 18
The MP 18 manufactured by Theodor Bergmann Abteilung Waffenbau was the first 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 Sturmtruppen, assault groups specialized in trench combat.
Rate of fire: ~350-500 round/min; 550-600 round/min (MP 28/II)
Designer: Hugo Schmeisser
Produced: 1918–1920s; 1928-Early 1940s (MP 28/II)
Place of origin: German Empire
Barrel length: 200 mm (7.9 in)
In service: 1918–1945 (Germany)
Manufacturer: Bergmann Waffenfabrik; Qingdao Iron Works; SIG (SIG M1920)
Credit to : C&Rsenal