The M16 is the U.S. military designation for the 5.56×45mm AR-15 rifle, developed by Eugene Stoner and the ArmaLite Corporation in 1957. Originally developed at the request of the United States Army for a lightweight, selective fire, .22 caliber rifle, the M16 is a highly flexible weapon that can be modified to use a variety of barrel lengths and calibers. It has been largely replaced by the lighter M4 Carbine in the US military but still sees use in training and is widely used by other militaries and Law Enforcement agencies throughout the world.
The M16 first saw field use during the Vietnam War and was adopted by the US Army in 1967 as the M16A1, replacing the M14 as the Army's standard infantry rifle. The weapon was further developed into the M16A2 in 1981, which incorporated a heavier barrel, new rounded hand guards, adjustable rear sights, and the replacement of the A1's full auto firemode with a three round burst setting. The fully automatic M16A3 and burst-fire M16A4 were introduced in 1996, which have integrated picatinny rails that allow various optical sights and other accessories to be used.
The M16 and its variants appear in ten installments of the Battlefield series. The original M16 appears in Battlefield Vietnam and Battlefield: Bad Company 2: Vietnam; the M16A2 in Battlefield 2, Battlefield: Bad Company, Battlefield: Bad Company 2, Battlefield Play4Free and Battlefield 2042's Battlefield Portal; the M16A3 in Battlefield 3, Battlefield Hardline, and 2042's Battlefield Portal; and the M16A4 in Battlefield 3 and Battlefield 4.
- M16, M16 Sniper (Battlefield Vietnam)
- M16A2 (Battlefield 2)
- M16 (Battlefield: Bad Company)
- M16 (Battlefield Heroes)
- M16A2, M16A1 (Battlefield: Bad Company 2, Bad Company 2: Vietnam)
- M16A2 (Battlefield Play4Free)
- M16A3, M16A4 (Battlefield 3)
- M16A4 (Battlefield 4)
- M16A3 (Battlefield Hardline)
- M16A2, M16A3 (Battlefield Portal)