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?
9×19mm Parabellum The 9×19mm Parabellum, also known as 9 mm Luger by the C.I.P. or 9 mm NATO by NATO (abbreviated 9mm, 9mmP, 9×19mm or 9×19) is a cartridge that was designed by Georg Luger and introduced in 1902 by the German weapons manufacturer Deutsche Waffen und Munitionsfabriken (DWM) (German Weapons and Munitions Factory) for their Luger semi-automatic pistol.
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.