The M60 General Pupose Machine Gun
The M60 General Purpose machine gun (GPMG) evolved as a result of designs started at the end of World War II, and replaced the Browning light and heavy machine guns in the US armory. The Allies had been impressed with the flexibility provided by the German GPMGs, and the American M60 thus incorporated a modified feed mechanism based on that of the German MG42, with the operating mechanism of the FG42 assault rifle.
The first prototype was the T44. When this proved disappointing, however, the feed mechanism was improved on a further two variants before the T161 emerged and was pronounced ready to enter service as the M60 GPMG. Moving away from the recoil mechanism of the browning machine guns, the M60 was designed as a gas-operated weapon. As the first round travels down the barrel, it pushes gas into the gas cylinder through a hole in the bore. The pressure generated in the cylinder then forces a piston down the chamber, moving the bolt back and bringing the next round into place. Once the firing pin hit’s the bullet and sends it speeding out of the barrel, the cycle is repeated for as long as the trigger is depressed.
With no gas regulator on the gun, however, there were drawbacks to this mechanism. Accumulated dirt or dust would slow the piston down and result in the M60 either jamming or “running away”. The latter term refers to the weapon continuing to fire even when the finger is removed from the trigger. An extremely unnerving problem to deal with during the heat of battle, the assistant M60 gunner would have to hold on to the ammunition belt in order to stop it feeding.
Besides the advantage of a quick-change barrel, one of the best features of the M60 was that the chromium=plated barrel itself had stellite liners for the first six inches along the muzzle from the chamber. This non-ferrous lining, combined with precision engineering, considerably increased the life-span of each barrel. The M60 could also be used as a heavy machine gun when mounted on M112 tripod.
As a result of the practical experience gained during the Vietnam War, a modified version of the basic M60 was introduced into service. Issued as the M60E1, this improved weapon remains the standard GPMG in the US Army. The M60E1 differs from the original M60 in a number of respects, including the attachment of the bipod to the rear of the gas cylinder, a modified rear sight, the addition of a die-cast feed cover and a new feed tray. A further improvement has been the addition of a hanger assembly that can be used in conjunction with a 100-round ammunition box. Known as a “bandolier”, this enables the M60 gunner to lay down fire while on the move.
M60 GPMG Stats:
Caliber: 7.62
Length: 1100cm
Weight: 10.48kg
Type of feed: 50-round link belt
System of operation: Gas
Rate of fire: 550 rounds per minute (cyclic); 200rpm (automatic)
Muzzle velocity: 860 meters per second
Maximum effective range: 800m (with bipod), 1800m (with tripod)
Ammunition: Ball, tracer, incendiary and armor-piercing