Figure 13-33.--The .50-caliber Browning machine gun (BMG), M2HB.
After the final adjustments are made, putting the
ADJUSTMENT OF FIRE
strike of the bullet at the aiming point, you must adjust
Adjustment of fire is the second fundamental point
the rear sight range plate. To do this, loosen the screw
of good marksmanship. Both the team leader and the
and move the plate until the 500-meter range mark
gunner must observe the strike of the bullets from the
coincides with the top left edge of the rear sight slide.
initial burst. They must be able to evaluate and adjust
Tighten the range plate screw and then record the
their fire rapidly if they are not on target.
amount of deflection for future reference.
When firing the biped-mounted gun, you adjust fire
by changing the position of your body. When firing the
tripod-mounted gun, you adjust fire by manipulating the
THE .50-CALIBER BROWNING
tripod traversing and elevating handwheel.
MACHINE GUN
Browning machine guns (BMGs) are standard
ZEROING-IN
weapons used throughout the Navy. The .50-caliber
BMG issued to naval activities is designated the M2.
The weapon is available with two types of barrels. An
Zeroing-in the M60 is similar to zeroing-in the
aluminum alloy "light" barrel is used for the aircraft
service rifle. Three rounds are fired at a target with a
version of the .50-caliber BMG, M2. A "heavy" barrel
predetermined range, generally of 500 meters. The rear
(HB) is issued for ship and surface craft use. Our
sight is set to 0 windage and to the corresponding range
discussion centers around the .50-caliber BMG, M2HB
(500 meters). After the three rounds are fired, the center
(fig. 13-33).
of the group is estimated. Next, adjust the windage knob
on the rear sight, as required, bringing the strike of the
bullet to the vertical center of the bull's-eye. One click
GENERAL DESCRIPTION
clockwise or counterclockwise of the windage knob is
a l-mil adjustment. This means that at 500 meters one
The .50-caliber BMG is a belt-fed, crew-served,
click will move the strike of the bullet 18 inches either
recoil-operated, air-cooled weapon. It can be set for
right or left. Next, you must change the elevation, if
automatic and semiautomatic fire. The .50-caliber BMG
required, by turning the elevation knob. A one-click
does not have any positive safeties.
adjustment clockwise or counterclockwise of the
elevation knob equals a l/4-mil change. At 500 meters
Ammunition is supplied to the receiver
this would be 4 1/2 inches.
(ammunition feedway) of the gun by a disintegrating
metallic link belt. The BMG is capable of alternate feed.
With the correct adjustments made to the rear sight,
Normally, the gun is fed from its left side; but by
the T & E mechanism is manipulated until the correct
repositioning certain component parts, the belt may be
sight picture is again obtained. You then fire one round
fed from the right side.
to confirm your sight setting. If the round misses your
point of aim, you must repeat the above procedure,
One person can operate the .50-caliber BMG.
making the necessary adjustments until the bullet strikes
However, two people, the gunner and assistant gunner,
where you are aiming.
are normally used. The gunner actually fires the weapon.
13-18
