While serving time in prison for murder, David Marshall "Carbine" Williams invented the floating chamber and the short-stroke piston, both of which use the high-pressure gas generated in or close to the breech of the firearm to operate the action of semi-automatic firearms like the M1 Carbine, which is widely credited with helping the Allies win World War II. His life story was dramatized in the 1952 movie Carbine Williams starring Jimmy Stewart.