A closed-bolt blow back-operated sub-machine gun, the Reising Model 50 saw action with the United States Marines in the Pacific as a substitute for the M1 Thompson, though they found their best success as defensive weapons for war-essential industries and as patrol carbines for American police forces. Blade front and elevation adjustable peep rear sights, with a flash hider/muzzle break, cooling fins on the barrel, three-line New Haven address near the ejector port, and three-position selector/safety on the right side. Smooth pistol grip stock with a cocking lever on the underside and a lightly ribbed buttplate.