M240 machine gun

Design and main characteristics

The M240 descends from the FN MAG family and retains the basic operating principles of a long-stroke gas system with a locked-breech rotary bolt. Important characteristics include:

• Belt feed system allowing linked ammunition for sustained fire.
• Air-cooled quick-change barrel to manage heat during prolonged engagements.
• Configurable mounts and sights so the same basic weapon can serve as a crew-served infantry gun or a vehicle/aircraft armament.

Variants and development

Over time several service variants have been produced to meet different requirements. Lighter and heavier models, variants optimized for infantry, maritime and aviation use, and versions with suppression or quick-change features have been fielded. U.S. services and allied forces have adopted specific models tailored to doctrine and platform needs.

History and adoption

The M240 entered U.S. service in the late 1970s as a replacement for older medium machine guns, and it has remained in widespread use since then. It has been manufactured under license and produced by several contractors to equip the Army, Marine Corps and other branches. The weapon earned a reputation for durability under harsh conditions.

Operational use and notable facts

In the field the M240 is employed for suppressive fire, area denial and as a defensive weapon on patrol vehicles and aircraft. It is typically operated by a small crew when used in a ground role but is light enough to be shoulder-fired from mounted positions. The M240 complements lighter squad automatic weapons by providing longer-range, sustained firepower. For information on infantry employment see infantry use.