PS Magazine - TB 43-PS-677

PS, The Preventative Maintenance Monthly

ISSUE 677

APRIL 2009
PS Magazine - TB 43-PS-677 - Page 11 of 33
19
PS 677
APR 09
Back Plate Hook
The back plate hook engages
the bolt latch release lever for
AUTO MODE. Sometimes the
hook can prevent the trigger
block from sliding between
FIRE and SAFE because the
hook is bent so that it holds the
bolt latch release too tightly
against the trigger assembly.
This happens during AUTO
MODE,
but
not
SINGLE
SHOT MODE.
Solve
this
problem
by
slightly
bending
the
hook
outward.
The
hook
should
keep the bolt latch release
lever in the full-down position
for AUTO MODE, but still
let the trigger block assembly
function correctly.
Do it like this:
1.
Push the bolt latch release lever completely in during AUTO MODE.
2.
Bend the hook slightly so that the trigger block assembly slides from FIRE to
SAFE while in AUTO MODE and the bolt stop clears the bolt during repeat-
±re operation.
3.
If the hook can’t be bent so that the bolt stop clears the bolt, then the metallic
tube, NSN 4710-00-726-5562, should be replaced.
Rivets Too Big
Sometimes the rivets for the upper frame handles are big enough that they interfere
with the trigger block. The trigger block can’t slide between FIRE and SAFE.
Correct this problem by ±ling the rivets enough so that they don’t interfere with
the trigger block. File between the face of the backplate and the rear side of the rivet.
When you’re done ±ling, put some solid ±lm lubricant, NSN 9150-00-754-0064, on
the rivets.
Backplate Lock Pins
There is also a possible problem with the lock pins on the backplate handle when
the trigger block is installed. If the upper right frame handle lock pin is installed
with the loop end on the left, it interferes with the trigger block sliding from FIRE to
SAFE. Solve the problem by reversing the lock pin so the loop end is on the right.
MWO
If MWO 9-1005-213-30-1’s trigger block hasn’t yet been applied to your M2s,
contact TACOM-RI’s MWO Coordinator at DSN 793-1054, (309)
782-1054, or
email:
vanya.cowser
@us.army.mil
Your support unit can install the trigger block kit, which comes with NSN 1005-
01-414-9706.
If you have M2 questions, contact TACOM-RI at DSN 793-
2108, (309) 782-
1054, or email:
walter.hilliard
@us.army.mil
Correcting
Trigger Block
Problems
M2 Machine Gun…
Correcting
Trigger Block
Problems
Field repairmen, if
the trigger block
from MWO 9-1005-
213-30-1 has been
applied to your
M2 machine guns,
there are a couple
of problems you
need to check
for
before
the
weapons leave the
arms room.
Trigger block prevents accidental fring
Bend hook
out slightly
so it doesn’t
interFere
with trigger
block
Yes
Oversized upper Frame handle rivets will need to be fled down
Loop should be on right
No
677.18-19.indd
1-2
3/3/09
3:12:30 PM
Click here for a copy of this article to save or email.
Back to Top
Back to Top