M16 Run Through The Jungle

The M16 rifle (officially designated Rifle, Caliber 5.56 mm, M16) is a family of assault 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 in 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.