The standard-issue M4A1 with SOPMOD Accessory Kit is a gas-operated, air-cooled, magazine-fed, selective fire weapon using 5.56mm rounds. It has a four-position telescoping stock, which is slightly larger than the M4, with a curvature at the end. The M4A1 is a fully-automatic variant of the M4 for use by special operations members, useful in urban warfare and preferred for Close Quarters Combat (CQB) because it is compact and powerful. The SOPMOD Accessory Kit includes a Rail Interface System (RIS); shortened quick-detachable M203 grenade launcher and leaf sight; KAC sound suppressor and back-up rear sight; AN/PEQ-2A visible laser/infrared designator; Trijicon’s ACOG and Reflex sights; and night vision sight.
The AR-15 (civilian) or M16 (military) uses 5.56mm rounds, has been in use by U.S. military forces since Vietnam. In 1967, the M16A1 version was in use until 1970, when it was supplemented by the M16A2. The U.S. Navy issued the M16A3, a fully-automatic variant of the M16A2, primarily for SEAL, Seabee and Security units. The M16A4 is now being supplemented; this variant includes a flattop receiver unit and Picatinny rail system. In 2003, the SOF Combat Assault Rifle (SCAR) or Mk 16 won the USSOCOM competition to find a new rifle for Special Operations Forces.
This Article is written by James Kara Murat