The Probert Encyclopaedia of Warfare

ARMALITE AR-15

The Armalite AR-15 (also known as the Colt M16) was an American gas direct action selective fire assault rifle derived from the Armalite AR-10 and designed by Eugene Stoner in response to requirements from the Infantry Board at Fort Benning for a lightweight selective fire assault rifle which could penetrate body armour or a steel helmet at 500 yards with accuracy at least as good as that of the M1 Carbine at 500 yards. Eugene Stoner's response was to design a lightweight, low impulse rifle firing a light-weight bullet at a high velocity, and this was first demonstrated to the Infantry Board in 1958. The Armalite AR-15 was chambered for the 5.56 mm x 45 cartridge which it took from a 20- or 30-round box magazine and fired at a muzzle velocity of 1000 meters per second at a cyclic rate of between 700 and 950 rounds per minute to an effective range of 400 meters. The Armalite AR-15 had a 508 mm long barrel and was fitted with a cylinder foresight and a flip aperture rearsight
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