Beretta M12S

The Bergmann MP-18 is the world's first practical submachine gun, designed by Theodor Bergmann in 1918. It was developed for the German Army during World War I to provide infantry with a high volume of close-range firepower. The MP-18 fires the 9x19mm Parabellum cartridge from a 32-round drum magazine. It uses a simple blowback action with an open bolt. The MP-18 established the basic concept of the submachine gun that would dominate close-quarters battle for decades.

The Sa vz. 25 is a variant of the Czechoslovak vz. 23 submachine gun featuring a folding metal stock instead of the fixed wooden stock on the vz. 23. It was designed for use by paratroopers, vehicle crews, and special forces who needed a more compact weapon. The vz. 25 shares the same telescoping bolt action and receiver as the vz. 23. Its folding stock folds to the side, reducing overall length for storage and transport. The weapon is chambered in 9x19mm Parabellum and feeds from a magazine inserted in the pistol grip.

The United Defense M42 is an American submachine gun designed by Carl Swebilius. It was produced for the Office of Strategic Services during World War II. The M42 uses a blowback action chambered in 9x19mm Parabellum and feeds from a 25-round box magazine. It features a wooden stock, a perforated barrel jacket, and a folding magazine well. The weapon was designed to be compact and concealable for clandestine operations. It was one of the first submachine guns designed specifically for intelligence and special operations work.