purpose machine gun system
The US Ordnance M60 is the US Army's general
purpose machine gun and entered service
in the late 1950s. The prime producer
was Saco Defense, then a subsidiary
of the Chamberlain Manufacturing Corporation (now General Dynamics Weapon Systems).
US Ordnance produces the M60 series under licence by General Dynamics Weapon
original design had some interesting features.
The straight line layout allows the operating
rod and buffer to run right back into the
butt and reduce
of the overall length. The large forehand grip is most convenient for carrying
at the hip and the folded bipod legs continue the hand protection almost
up to the muzzle. The gun can be stripped
using a live round as a tool.
M60 fires in full automatic mode only, at
a cyclic rate of 500-650 rds/min. This is
slow enough for an accomplished firer to
get off a single round.
The tactical rate rapid is 200 rds/min.
M60 originally used the German MG42 feed
system employing an arrangement of inner
and outer feed pawls driven by a bolt operated
feed lever constructed
to move in opposite directions, moving the belt in two stages as the
bolt moved back and forward again.
the M60 was developed, the feed system changed.
The friction roller at the back of the bolt
was retained as was the feed arm on top of
in which it operated. The inner and outer pawl system was abandoned
and a single pawl system substituted. In
this the roller, carried by the
swings the feed arm to the right. The feed arm is pivoted so that the
carrying the feed pawl slips to the left over the next round to be
fed. As the bolt goes back the pawl moves
to the right and lifts the entire
belt through one complete pitch.
the M60, the gas cylinder and the bipod are
both permanently attached to the barrel.
The M60E3 has a barrel with gas cylinder
only, as the
to the front of the receiver assembly. The barrel is chromium plated
and also has a Stellite liner in the 152 mm (6 in) of barrel forward
M60, having a fixed foresight, makes adjustment
for zeroing on the rearsight. This means
that the number one on the gun must first
is in the gun and secondly know the correct zero setting for both
line for that barrel. In practice this means all barrels are fired
from a common zero and the consequent loss of accuracy is accepted.
variety of fire-control systems and mounts
is available. Day and night sights, laser
aiming devices and laser range-finders
the weapon brackets with the US Army dovetail mounting configuration
and advanced throw-lever attachment device, without loss of zero.