M85 Machine Gun
AAI Corporation · Machine Gun · Out Of Production · 1959
Also known as: T175E2, M85C
Overview
The M85 is an American .50 caliber (12.7x99mm NATO) heavy machine gun designed by AAI Corporation to replace the Browning M2HB with a shorter, lighter weapon suitable for the cramped cupola mounts of armoured vehicles. It is recoil-operated, fires from an open bolt and offers two selectable cyclic rates - a lower rate for ground targets and a much higher rate for anti-aircraft use. Reliability shortfalls limited its adoption, and it was eventually phased out in favour of the M2.
Specifications
| Weight (empty) | 29480 g (1039.9 oz) |
| Overall Length | 1384 mm (54.49") |
| Barrel Length | 1016 mm (40.00") |
| Action Type | Short Recoil |
| Firing Mechanism | Open Bolt |
| Magazine Type | Belt |
| Muzzle Velocity | 880 m/s (2887 fps) |
| Muzzle Energy | 16220 J (11963 ft·lbf) |
| Effective Range | 2196 m (2402 yd) |
| Maximum Range | 6703 m (7330 yd) |
| Rate of Fire | 500 rpm |
| Barrel Rifling | Right Hand |
| Frame Material | Steel |
| Barrel Material | Steel |
| Finish | Phosphate |
Calibers
- 12.7x99mm NATO · primary · 12.7mm NATO — also known as .50 BMG, .50 Browning, 12.7x99mm, .50 Caliber
Features
- Firing modes: Full Automatic
- Feed systems: Disintegrating Link Belt
- Safety mechanisms: Manual Safety
- Features: Belt Fed, Left Or Right Hand Feed, Dual Cyclic Rate, Fixed Headspace, Compact Receiver, Cupola Mount, Solenoid Fired
Service history
Operators
- United States Army · adopted 1959 · as M85
- United States Marine Corps
Conflicts
- Vietnam War (1955-1975)
Production
Production years: 1959-1980s
Produced as a vehicle-mounted .50 caliber gun; limited adoption due to reliability issues, later replaced by the M2
Origin
Country of origin: United States
Discontinued: 1997
Notes
Fielded primarily on the cupola of the M60 series of main battle tanks and on the LVTP-7 amphibious assault vehicle. The dual-rate mechanism gave roughly 400-500 rpm against ground targets and a much higher rate against aircraft.
Background
The M85 was meant to retire the legendary Browning M2 by being shorter and lighter for tank cupolas - but it never matched 'Ma Deuce' for reliability, and the gun it was built to replace ultimately outlived it in US service.