What cartridge, also known as 9 mm Luger by the C.I.P. or 9 mm NATO by NATO, is used in the submachine gun the MP 40?
MP 40 The MP 40 ("Maschinenpistole 40") was a submachine gun chambered for the 9×19mm Parabellum cartridge. It was developed in Nazi Germany and used extensively by the Axis powers during the Second World War.
Interdynamic MP-9 The Interdynamic MP-9 is a blowback-operated, fully automatic 9 mm caliber firearm, classified by BATF as a submachine gun. It is made of inexpensive molded polymer and stamped steel parts. 10-, 20-, 32-, 36- and 50-round magazines are available.