The M16 rifle, officially designated Rifle, Caliber 5.56 mm, M16, is a United States military adaptation of the Armalite AR-15 rifle. The original M16 was a select-fire, 5.56×45mm rifle with a 20-round magazine. The M16 has also been widely adopted by other military groups around the world. Total worldwide production of M16s has been approximately 8 million, making it the most-produced firearm of its 5.56 mm caliber. The U.S. Army has largely replaced the M16 in combat units with the shorter and lighter M4 carbine, and the U.S. Marine Corps approved a similar change in October 2015.
Technical Data Weight 7.18 lb (3.26 kg) (unloaded) 8.79 lb (3.99 kg) (loaded) Length 39.5 in (1,003 mm) Barrel length 20 in (508 mm) Cartridge 5.56×45mm NATO Action Gas-operated, rotating bolt (direct impingement) Rate of fire 12–15 rounds/min sustained 45–60 rounds/min semi-automatic 700–950 rounds/min cyclic Muzzle velocity 3,110 ft/s (948 m/s) Effective firing range 550 m (601 yd) (point target) 800 m (875 yd) (area target) Maximum firing range 3,600 m (3,937 yd) Feed system 20-round detachable box magazine: 0.211 lb (96 g) empty / 0.738 lb (335 g) full 30-round detachable box magazine: 0.257 lb (117 g) empty / 1.06 lb (480 g) full) Beta C-Mag 100-round double-lobed drum: 2.20 lb (1,000 g) empty / 4.81 lb (2,180 g) full) Sights Iron sights