The Erma Werke MP40 is a germany-made blowback submachine gun chambered in 9mm Luger, introduced in 1940. Primary use: military, sport. Type: Submachine Gun Action: Blowback Caliber: 9mm Luger Capacity: 25 Year introduced: 1940, Germany Weight: 88 oz Overall length: 24" Status: Discontinued Military use: Yes Intended use: military, sport