MP 40

The MP 38 and MP 40 (MP designates Maschinenpistole, literally "Machine Pistol"), 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.

Read more about MP 40:  Development, Design, Copies and Post-war Usage, Variants and Developments, Users