XM312 Advanced Crew Served Weapon
XM307K50 Advanced Crew Served Weapon
12.7mm Weapon System

The XM312, developed by General Dynamics Armament and Technical Products, is a lightweight, portable 12.7mm/.50 caliber machine gun that provides increased accuracy, effectiveness, and lethality over existing heavy machine guns. The XM312, originally known as the XM307K50, offers a significant difference from its predecessor in that the gun and tripod weighs slightly more than 42 pounds compared to the .50 caliber M2 machine gun with a total system weight of 128 pounds. The XM312 can accept belt-fed ammo from either the left or right. In the XM312 the gun barrel moves and not the bolt, reducing the recoil of the weapon, and with the slower rate of fire, the gun can function for an indefinite period without damage. Unlike the .50 caliber M2 machine gun it does not require headspace or timing adjustments. The XM312 is 9 times more accurate than the M2.

The design of the XM312 was based on the recoil-reducing action developed for 25mm Objective Crew Served Weapon (OSCW), which later became the XM307 ACSW. The barrel was locked by the conventional rotating bolt, which was operated by a more or less conventional gas system. The bolt group moved within the barrel extension, which, along with the barrel and gas system, can recoil inside the gun housing. The XM312 fires from the open bolt, and at the moment of fire the recoiling group (barrel, barrel extension, gas system and gas drive) is in its rearmost position. When gun is fired, special spring first begin to move recoiling group forward. The bolt is then released, stripping the cartridge into the barrel, locking it in place. The cartridge is then fired, while the recoiling group is still on the move forward. The recoil of the shot first has to overcome the inertia of the recoiling group, and only then group began to recoil back, compressing the return spring. At the same time gas drive unlocks the bolt, and retracts it within the barrel extension, extracting and ejecting a fired case. This somewhat complicated design results in significantly reduced recoil, and in conjunction with muzzle brake, in lightweight, but stable construction. The price of this reduction in recoil is complicated (and expensive) construction and low cyclic rate of fire. The feed uses existing disintegrating metallic link belts and the XM312 can be fed from either the left or the right side.

The M307 system can be quickly and easily converted into the XM312 12.7mm / .50-caliber machine gun. The XM312 can be converted back to the M307 in 2-4 minutes by changing 4 parts. The ability to convert the weapons back and forth while in field gives the front-line soldier flexibility in choosing weapons to meet the mission. By producing a family of weapons utilizing a common platform, General Dynamics Arament and Technical Products reduced user cost, provided a diverse weapon to meet situational needs and increased mission-critical space.

The XM312 shoots, handles and maintains like a light machine gun. The accuracy and steadiness of the XM312 during firing is notable. It has a sight, and it does npt move much because there is not much kick. This allows firers to keep their eyes right on the crosshairs. It is a very easy weapon to shoot. The ability to lay the first round on target is impressive. It would be very beneficial downrange. There is zero time for the enemy to see what is going on. That also means a more optimal use of ammunition. It conserves a lot of rounds because of the accuracy. Shooters would be able to hit the target every time.

The XM312's advancement over existing .50 caliber (12.7mm) machine guns is achieved by a significant reduction in weight, which contributes to the weapon's ability to be easily transported in small soldier units, and recoil mitigation technology, which increases ground-mounted accuracy. The XM312 was one of the lightest .50 caliber (12.7mm) machine guns on the market at the time of its introduction. Decreased cyclic rate of fire, which was more than 2 times lower than on other .50 caliber guns, made the gun strictly an anti-ground weapon. The low rate of fire would made it ineffective against fast-moving targets like helicopters and low-flying aircrafts. The practical rate of fire, however, is quoted to be no less than of the existing .50 caliber M2 maachine gun, around 40 rounds per minute. The XM312 also would be no less (if not more) accurate than the M2 machine gun. Utilization of advanced magnification and night-vision sights would allow for effective use at ranges up to 2,000 meters.