The M249 squad automatic weapon (SAW), formally Squad Automatic Weapon, 5.56 mm, M249 is an American version of the Belgian FN Minimi. The M249 is manufactured in the United States and is used by all branches of the U.S. Armed Forces. The gun was introduced in 1984 and judged the most effective weapon to address the lack of automatic firepower in small units. It was the only one of a number of candidate designs to successfully pass tests set by the U.S. government. Tactically, it is employed at squad level and is operated by a designated automatic rifleman. The gun provides the heavy volume of fire of a machine gun with accuracy approaching that of a rifle.
The M249 is gas-operated and air-cooled. It has a quick-change barrel so an overheated or jammed barrel may be rapidly replaced by the gunner. A folding bipod is attached near the front of the gun, though a heavy fixed tripod is also issued. It can fire both linked ammunition and ammunition kept in magazines.
M249 SAWs have been issued during every major United States conflict since the 1991 Gulf War. Soldiers generally approve of the weapon's performance, though there have been many reports of clogging with dirt and sand. Due to the weight and age of the weapon, the U.S. Marine Corps (USMC) is considering designs for an infantry automatic rifle (IAR) which is planned to complement and partially replace the M249 in their service.