FM 23-45 Basic Field Manual
14
Tripod Set tripod firmly
with no lost
motion. Verify
that traversing
bar sleeve latch
is properly
seated.
Keep firmly
set.
Examine Clean and oil.
Belts and
ammunition
Secure sufficient
supply of
ammunition.
Inspect
ammunition.
Keep belts dry
Keep belt in
line with feed
opening.
Watch
ammunition
supply
Clean, repair,
and refill all
belts. Separate
live rounds
from empty
cases. Inspect
ammunition.
Oil See that oilcan is
full
Refill oilcan. Refill oilcan.
Spare parts
and tools
Keep clean and
oiled. See that
kits are complete
Keep within
reach
Make
repairs.
Replace
broken or
worn parts.
Check, replace
broken or
missing parts,
clean, and oil.
S
ECTION IV
MECHANICAL FUNCTIONING
■27. G
ENERAL. — The soldier should have a practical working knowledge of the
mechanical operation of the machine gun so that he will be able to keep it in action
during combat. Although many parts of the gun operate simultaneously, the subject of
functioning is divided into phases to facilitate instruction. The explanation of
mechanical functioning begins with the gun assumed to be loaded and ready to fire.
a
. To half load. — With cover open or closed, enter belt through feedway from left to
right. Pull belt through feedway until the first round is in place on the right of
beltholding pawl. Close cover if open. Pull bolt fully to the rear and release it.
b
. To load. — Load is executed the same as half load except that bolt is pulled to the
rear and released twice.
c
. To unload. — Raise cover, remove belt, pull bolt to the rear and hold it, look or feel
to see that there is no ammunition in the gun, lower extractor, release bolt, lower
cover, and then pull trigger.
d
. To clear gun. — Raise cover, remove belt, pull bolt to the rear and hang it in its
rearmost position by engaging extractor cam plunger in rear of extractor feed cam, and
inspect the gun to see that there is no ammunition in it. As an additional precaution, a
wooden clearing block will be inserted between the face of the bolt and the rear end of
the barrel.
■28. T
RIGGER ACTION. — As the trigger is pivoted, its rear end is raised if its forward
end is lowered. The trigger cams on the front end of trigger, through their engagement
with cams on sear, force sear down against the action of sear spring until the shoulder
of firing pin is released by sear notch. The firing pin spring then forces firing pin
forward to strike primer.
■29. B
ACKWARD MOVEMENT OF RECOILING PARTS (figs. 9 and 10). — The explosion
forces the recoiling parts (barrel, barrel extension, and bolt) backward about 5/8 inch.
During the first half of this movement the parts are locked together.
