Figure 13-34.--The 30-caliber BMG on an M3 tripod mount.
The assistant gunner helps to load and reload the
Weight of barrel . . . . . . . 24 pounds
ammunition into the receiver. Other personnel
(approximately)
ammunition bearers-can be used to keep the assistant
Weight of tripod mount
gunner supplied. Speed, skill, and teamwork are
M3 (w/traversing and
important.
elevating mechanism
and pintle w/bolt) . . . . . . 44 pounds
The force for recoil is finished by the expanding
gases of the fired cartridges. The recoil operation is
Total weight of gun,
controlled by various springs, cams, and levers within
complete, on tripod
the gun.
mount, M3 . . . . . . . . . . 128 pounds
(approximately)
Most of the barrel and receiver is exposed to the air
to cool the .50 caliber BMG. Perforations (holes) in the
Maximum range
barrel support allow air to circulate around the breech
(M2 ball) . . . . . . . . . . . 6800 meters
(approximately)
end of the barrel. A heavy barrel (HB) is used to retard,
or slow down, early overheating.
Maximum effective
range . . . . . . . . . . . . . 1830 meters
The .50-caliber BMG has a leaf type of rear sight.
It is graduated in both meters and mils for ranges from
Rates of fire:
100 to 2600 meters and from 0 to 62 mils. A windage
Sustained . . . . . . . . . . . 40 rounds or less
knob permits deflection changes of 5 mils right or left
per minute
of the center. The front sight is a semifixed blade type
Rapid . . . . . . . . . . . . . 40 rounds or more
with a cover.
per minute
Because of its size and weight, the .50-caliber BMG
Cyclic rate of fire . . . . . . 450 to 550 rounds
usually needs some type of mounting support. Figure
per minute
13-34 shows the M3 tripod mount arrangement. Other
devices or stands may also be used. The primary reason
Muzzle velocity
for mounting the weapon is to increase its firing
(M2 ball) . . . . . . . . . . . 3,,050 feet/second
accuracy.
(2,,080 mph)
The main characteristics of the .50-caliber BMG are
Length of gun, overall . . . . 65 inches
(approximately)
listed below.
Length of barrel . . . . . . . 45 inches
Weight of receiver group . . 60 pounds
13-19
