M16 rifle

M16
M16A2, multi-sided view
Type	Assault rifle
Place of origin	United States
Service history
In service	1964–present[1]
Used by	See Users
Wars	See Conflicts
Production history
Designer	Eugene Stoner (AR-10)[2] L. James Sullivan (AR-15)[3]
Designed	1959[4]
Manufacturer	Colt's Manufacturing Company Daewoo Precision Industries FN Herstal Harrington & Richardson General Motors Hydramatic Division Elisco U.S. Ordnance
Produced	1963–present[1] [obsolete source]
No. built	c. 8 million as of 2011[1]
Variants	See List of Colt AR-15 and M16 rifle variants
Specifications (M16)
Mass	unloaded: 6.37 lb (2.89 kg) (M16A1) 7.5 lb (3.40 kg) (without magazine and sling) (M16A2)[5] 7.5 lb (3.40 kg) (M16A4) 8.81 lb (4.00 kg) (loaded with 30 rounds and sling)[6]
Length	38.81 in (986 mm) (M16A1) 39.63 in (1,007 mm) (M16A2) 39.37 in (1,000 mm) (M16A4)
Barrel length	20 in (508 mm)
Cartridge	5.56×45 mm NATO
Caliber	5.56 mm (.223 in)
Action	Gas-operated (Expansion of gas within piston inside bolt carrier), closed rotating bolt
Rate of fire	700–800 rounds/min cyclic sustained (M16A1)[7] 700-900 rounds/min cyclic sustained (M16A2, M16A3)[8] 800 rounds/min cyclic sustained (M16A4)[8]
Muzzle velocity	3,150 ft/s (960 m/s) (M855A1 round)[9]
Effective firing range	550 m (601 yd) (point target)[10] 800 m (875 yd) (area target)[11]
Maximum firing range	3,600 m (3,937 yd)
Feed system	STANAG magazine 20-round detachable box magazine: 0.211 lb (0.096 kg) (empty) / 0.738 lb (0.335 kg) (full) 30-round detachable box magazine: 0.257 lb (0.117 kg) (empty) / 1.06 lb (0.48 kg) (full) 40-round detachable box magazine 60-round detachable box magazine Beta C-Mag 100-round drum magazine: 2.2 lb (1.00 kg) (empty) / 4.81 lb (2.18 kg) (full)
Sights	Iron sights: Rear: aperture; L-type flip Front: wing-protected post Various aiming optics

The M16 rifle (officially designated Rifle, Caliber 5.56 mm, M16) is a family of military rifles adapted from the ArmaLite AR-15 rifle for the United States military. The original M16 rifle was a 5.56×45mm automatic rifle with a 20-round magazine.

In 1964, the M16 entered US military service and the following year was deployed for jungle warfare operations during the Vietnam War.^[12] In 1969, the M16A1 replaced the M14 rifle to become the US military's standard service rifle.^[13] The M16A1 incorporated numerous modifications including a bolt-assist, chrome-plated bore, protective reinforcement around the magazine release, and revised flash hider.^[12]

In 1983, the US Marine Corps adopted the M16A2 rifle, and the US Army adopted it in 1986. The M16A2 fires the improved 5.56×45mm (M855/SS109) cartridge and has a newer adjustable rear sight, case deflector, heavy barrel, improved handguard, pistol grip, and buttstock, as well as a semi-auto and three-round burst fire selector.^[14] Adopted in July 1997, the M16A4 is the fourth generation of the M16 series. It is equipped with a removable carrying handle and Picatinny rail for mounting optics and other ancillary devices.^[15]

The M16 has also been widely adopted by other armed forces around the world. Total worldwide production of M16s is approximately 8 million, making it the most-produced firearm of its 5.56 mm caliber.^[16][1] The US military has largely replaced the M16 in frontline combat units with a shorter and lighter version, the M4 carbine.^[17][18] In April 2022, the U.S. Army selected the SIG MCX SPEAR as the winner of the Next Generation Squad Weapon Program to replace the M16/M4. The rifle is designated XM7.^[19]