M2 .50 Caliber Machine Gun
The Browning M2 .50 caliber (12.7mm) machine gun is an automatic, belt-fed, recoil operated, air-cooled, crew-operated machine gun. The M2 is crew transportable with limited amounts of ammunition over short distances. The gun has a back plate with spade grips, trigger, and bolt latch release. The gun is equipped with leaf-type rear sight, flash suppressor and a spare barrel assembly. By repositioning some of the component parts, ammunition may be fed from either the left or right side. A disintegrating metallic link belt is used to feed the ammunition into the weapon. The gun is capable of being modified to fire in single-shot mode, as well as automatic fire.
The gun may be mounted on ground mounts and vehicles as an anti-personnel and anti-aircraft weapon. Associated components are the M63 anti-aircraft mount and the M3 tripod mount. The flexible version is used as a ground gun on the M3 tripod mount or various naval mounts. The M48 turret type, fixed type, and soft mount versions are installed on mounts of several different types of combat vehicles and ships. The weapon provides automatic weapon suppressive fire for offensive and defensive purposes. This weapon can be used effectively against personnel, light armored vehicles; low, slow flying aircraft; and small boats.
The M2E2 Quick Change Barrel (QCB) Kit enhances the M2 with new features and design improvements that make the weapon easier and safer to use. The kit features fixed headspace and timing reduce the time required to change the barrel and eliminate the need to reset headspace. The quick change barrel itself has a removable carrying handle that provides soldiers with a more expedient and safer way of changing barrels. The barrel also has a flash hider that reduces muzzle flash, making the M2 night friendly. The kit was incoprorated into the type standardized M2A1 design, which also featured a modified bolt and trigger block. By Spring 2011, all new production weapon were to be built to the M2A1 standard and older weapons would be retrofitted witht he QCB Kit.
The M2A1's fixed headspace and timing enhancement resolves the number one safety issue for soldiers operating the weapon system. Headspace is the distance between the face of the bolt and the base of the cartridge case, fully seated in the chamber. Timing is the adjustment of the gun so that firing takes place when the recoiling parts are in the correct position for firing. The original M2 requires soldiers to manually set headspace and timing before firing, after assembly, and after required barrel changes when the barrel becomes extremely hot from high volumes of fire. Improper adjustment can damage the weapon and cause serious injury to the user. Fixed headspace and timing reduces operator risk and eliminates the need for soldiers to master and execute this time-consuming procedure.