XM312 / XM307K50 : .50 Caliber Lightweight Machine Gun

Weight:
35 pounds (16 kg) max. (weapon only)
53 pounds (24 kg) max. (ground mount system).
Dimensions: 9.9W x 7.2H x 61.5L max. inches (25.1 mm x 18.3 mm x 1562 mm)(52.5L, 1334 mm) charged).
Portability: Man portable or vehicle mountable.
Stability: Up to 18 inch (460 mm) tripod height.
Operation: Currently a hybrid gas & recoil operating group. Gas powers the bolt mechanism while recoil drives the barrel/barrel extension and the feed system. Design changes are underway to eliminate the gas system totally to provide increased reliability and reduced complexity.
Environmental: Operationally insensitive to conditions.
Reliability: 6,000 MRBF (threshold) / 10,000 MRBF (objective).
Rate of fire:
260 shots per minute (4.3 hz)(cyclic).
40 shots per minute (0.7 hz)(sustained, without barrel change). In Burst of 5 to 7 rounds, the same as the M2HB.
Dispersion: Less than 1.1 miliradian, one sigma radius.
Range: Lethal and suppressive out to 2,000 meters.
Ammunition: .50 BMG M33 ball, M8, M20 & Mk211 API, M903 SLAP.
Recoil: 300 foot-pounds (407 J)(similar to the 7.62 mm M240).
Feed system: Weapon-mountable ammunition can or feed from any can using bellmouth attachment. M9 rear stripping link - common with current M2 ammunition. Left hand feed, right hand eject of cases and links.


The XM312 is a modern heavy machine gun chambered for the 12.7 × 99 mm NATO cartridge which is derived from the XM307 25 mm autocannon. It was designed in response to a request by the US military for a replacement for the aging M2HB heavy machine gun, and as a complement to the heavier XM307. It is quickly capable of being converted to an XM307 with a small number of parts and a few minutes of work at the unit level (and vice versa from the XM307). Procurement of the XM312 will allow easier use of the XM307, as only the related kits would have to be adopted. Two years ago field testing began with the XM312, but the test results were not encouraging because of the very low rate of fire of only 260 rounds per minute, so it is unlikely the XM312 will enter service with the U.S. Military.

The XM312, formerly known as the XM307K50, is a lightweight .50 caliber (12.7mm) machine gun being developed by General Dynamics to provide support for US Army objective forces. It features increased accuracy, effectiveness and lethality over current machine guns.This item can be converted to a 25mm grenade launcher taking less than 5 minutes and changing 6 parts. In fact, the XM312 machine gun is a derivative of the XM307 25mm grenade weapon system being designed for the US Army Objective Force.