PS Magazine - TB 43-PS-568
PS, The Preventative Maintenance Monthly
ISSUE 568
MARCH 2000
PS 568
43
MAR 00
PS 568
42
MAR 00
M29A1, M30 Mortars . . .
Rotate
azimuth
to 3,800
n M29A1 or M30 mortar with a
bum sightunit is a mortar that’s shoot-
ing blind. That means you won’t hit
your target and you could hit your own
people. Here’s how to keep your M53/
M53A1 sightunit seeing clearly:
When you boresight, use the flat
tip screwdriver that’s part of the
mortar’s BII. Other screwdrivers can
round out the screws’ slots. Then you
can’t boresight until the screw’s
replaced.
But leave the elbow telescope screw
alone. Monkeying with it can damage
the telescope’s seal.
When you’re finished boresighting,
make sure the coarse elevation scale
and elevation knob screws are tight. If
they’re even slightly loose, the shock
from firing will throw off the sightunit’s
accuracy. A few more shocks and the
screws fall out. No more boresighting.
Be careful stowing the sightunit in
its case. You may think you’ve posi-
tioned the sightunit OK, but unless you
do it just right you may damage the
lamp bracket holder. More likely, you
could poke a hole in the case. Then
dirt and moisture get a shot at the whole
sightunit.
If the case does have a hole, tape the
hole inside and out with duct tape until
you can get a new case, NSN 1240-
00-823-5611.
Be especially careful to rotate the
azimuth to 3,800. And make sure the
instrument light cables are positioned
so they won’t be pinched by the case
lid and so they can’t damage the
eyeshield.
Use flat tip
screwdriver
to turn
boresight
screws
Leave this screw alone
nice
shooting,
hawkeye!
man, I
can’t even hit
the proverbial
broad side
of a
barn
!
What’s
wrong with
you ?
Don’t
blame
me.
with
a little pm, i'd
be a
barn
burner!
Tape holes
and cracks
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