coach gun

A coach gun is a double-barreled shotgun, generally with side-by-side barrels 18 to 24 inches (460 to 610 mm) long. It was called a "cut-down shotgun" and a "messenger's gun" from the use of such shotguns on stagecoaches by shotgun messengers in the American Wild West. The name "coach gun" is a modern term used by gun-collectors.