Developed and introduced in 1917 (and designated the 1918 to prevent confusion with the Model 1917 machine gun), the Browning Automatic Rifle became a signature American weapon for generations, seeing limited action in World War I, on both sides of the law during the "Public Enemy" era of crime, and heavy use in World War II, Korea, and Vietnam. Blade front and folding ladder rear sights, with "W/(flaming bomb)/1-19" marked on the top front of the barrel with eagle and flaming bomb Ordnance proofs at the breech. A set of British proofs are present on the right side of the receiver and barrel, the latter also bearing caliber and pressure stamps. The top of the receiver bears the 5-line Winchester nomenclature ending in "PATENT APPLIED FOR", with "F A S" pattern (semi/full/safe) selector mechanism with the spring loaded catch to keep the operator from accidentally putting the rifle on "safe" when flipping to full automatic, and the early pattern trigger housing which lacks the magazine guide "wings" introduced after World War I. Fitted with a checkered hardwood forearm and a smooth pistol grip stock with a steel buttplate.