Browning automatic rifle (BAR)

One of the most important infantry weapons of World War II, the BAR was introduced in World War I and modified, as the M1918A2, in 1940. It was this version that was used in World War II combat. The new model could be fired only in two automatic modes, slow (300 to 450 rounds per minute) or fast (500 to 650 rounds per minute). Because the U.S. Marine Corps preferred to use the weapon in semiautomatic mode, none of the 1940 modified BARs were used by the corps. The original World War I model of the BAR lacked the later version's buffer spring in the butt and was, therefore, fatiguing for the shooter. Introduced in the 1940 variant, the buffer spring not only increased shooter endurance, it also improved accuracy by reducing recoil. Nevertheless, the BAR was a large weapon, and it was often mounted on its own detachable folding bipod. During World War II, the army infantry squad, consisting of nine men, was tactically organized around a single BAR. The marine squad consisted of 13 men divided into three fire teams, each of which was organized around a BAR. Specifications for this air-cooled, gas-operated, magazine-fed, shoulder-type infantry weapon include: Caliber: .30 (30–06) Muzzle velocity: 2,800 feet per second Capacity: 20-round detachable box magazine Weight: 18.5 pounds Length: 47 inches Rate of fire: 550 rounds per minute Effective range: 600 yards