Type Submachine gun Place of origin United States Service history In service 1941–1953 Wars World War IIHukbalahap RebellionMalayan EmergencyCosta Rican Civil WarVietnam War Production history Designer Eugene Reising Designed 1940 Manufacturer Harrington & Richardson Produced 1941–1945 Specifications Mass 3.1 kg (6.83 lb) (M50)2.8 kg (6.2 lb) (M55) Length 959 mm (37.8 in)787 mm (31.0 in) stock retracted (M55) Barrel length 279 mm (11.0 in) (M50) Cartridge .45 ACP Action Delayed blowback, closed bolt Rate of fire 550 rounds/min (M50)500 rounds/min (M55) Muzzle velocity 280 m/s (919 ft/s) Maximum firing range 300 yards Feed system 12- or 20-round detachable box magazine, 30-round aftermarket detachable box magazine Sights Front blade, rear notch Continue reading Reising Model 50