M85 machine gun

The M85 is a heavy machine gun firing .50 BMG ammunition that was used primarily weapon for turreted applications in armored fighting vehicles. It was intended to replace the venerable M2 machine gun with a smaller and much lighter weapon, suitable for use inside fighting vehicle, as opposed to only on external mounts. It was used on the M60 series of tanks and the LVTP-7 amphibious landing vehicle. In practice the gun was found to be highly unreliable, and was removed from service.

Design and development
Intended as a smaller, lighter, more capable replacement for the venerable M2 Browning machine gun, the M85 was produced by General Electric. The weapon was developed with selectable high and low rates of fire for engagement of both ground and air targets, a feature lacking in the older M2.

The M85 was the standard heavy tank machine gun for the M60 series, and was also used on the LVTP-7 amphibious vehicle. It is an air-cooled, recoil operated machine gun, has a short receiver and quick change barrel, and can be configured for left or right hand feeding. The M85 is significantly lighter than the M2, and significantly smaller, a prime consideration for its intended role inside the cramped interiors of armored vehicles. Firing and charging are achieved by pull on one of two color-coded pull chains (black for charging and red for firing), or by means of a solenoid.

The M85 used the M15 push-through link to feed ammunition as opposed to the M2 or M9 pull-out links used on the M2 and M3 Browning machine guns. This created issues with ammunition supply in use, since despite the same .50 BMG cartridges being used in both patterns of machine gun the ammunition was supplied already packed on links and re-linking was not practical in the field.

In service the M85 was found to be unreliable and extremely complex compared to the M2 machine gun. The weapon was not fitted to the M1 Abrams, and was replaced by the M2 machine gun on the improved AAVP-7. An attempt was also made to make a version of the M85 that would replace the M2 in the infantry role was designated the M85C, and features standard spade grips and can be fitted to the M3 heavy tripod. Like the M85 the M85C was extremely unreliable and unpopular and this weapon was not adopted.

The M85 was also tested by the United Kingdom under the designations XL17E1 and XL17E2. They were equipped with special purpose barrels and evaluated as ranging machine guns. The weapon was not adopted for use on any British vehicles.

M85

 * Basic weapon, designed for mounting inside vehicle cupolas

M85C

 * Flexible infantry variant with sights and spade grips