The MP40 (Maschinenpistole 40) is a German WWII-era 9×19mm submachine gun. It was initially designed by Heinrich Vollmer in 1938, and production started in 1940. The weapon features open-bolt mechanism, low cost stamped metal parts, synthetic furniture, and a bottom-folding stock. Feed system is standard 32-round magazine.
This tag implicates submachine_gun (learn more).