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.
Heckler &amp; Koch P9 The HK P9 is a semi-automatic pistol from Heckler & Koch in 9×19mm Parabellum and the first to use a variation of H&K's roller delayed blowback system in a pistol format and polygonal rifling now common in H&K designs. Design began around 1965 and production ran between 1969 and 1978. Only 485 single-action P9's were produced and were discontinued in 1970. A traditional double action version, the P9S (the "S" standing for "Spannabzug", or "double-action trigger") was manufactured in greater numbers.