PS Magazine - TB 43-PS-707

PS, The Preventative Maintenance Monthly

ISSUE 707

OCTOBER 2011

PS Magazine - TB 43-PS-707 - Page 22 of 33
40
PS 707
OCT 11
For the chamber, use the chamber brush and CLP. If your M249 or M240 has
trouble extracting, a quick cleaning of the chamber usually ±xes the problem.
CLPdoes a good job of cleaning off carbon, but it also does a good job of collecting
carbon. So never use CLP—or any of the other lubes—on the barrel’s gas regulator
hole, the gas regulator, the gas cylinder, or the op rod’s piston end. Clean carbon off
those parts with the scraper only—no CLP.
It’s OK to use CLP to clean the barrel, the chamber, the rest
of the op rod, and the bolt face, but wipe them dry before ±ring.
Another excellent way to ±ght carbon in the gas system is
to change the barrel on both the M249 and M240 when you’re
supposed to. For the
M240
, that means changing barrels every
10 minutes during sustained ±re (100 rounds per minute) and
every two minutes during rapid ±re (200 rounds per minute).
For the
M249
, during both sustained ±re (40 rounds per
minute) and rapid ±re (100 rounds per minute), change the
barrel every 200 rounds.
What you
don’t
want to do with the
M240
is change the gas
regulator setting from #1. The #2 setting produces much more
carbon in the gas system. The #2 setting should be used only in
combat emergencies.
If your scraper and elbow grease just won’t clean out all the
carbon, ask your armorer for help.
I
f carbon is allowed to build and build inside the gas systems of the M249 and M240
machine guns, they ±re slower and slower and then not at all.
The key to gas relief for both machine guns is the scraper. Each scraper part is
designed to scrape away carbon from different parts of the gas system. And the
sooner you use the scraper, the easier the job is. The longer carbons sits, the harder it
gets. It eventually becomes like enamel.
Clean center hole of regulator
with POINTED END, turning it
clockwise and pushing in until
scraper hits bottom
Clean two grooves on regulator
with PROTRUDING TIPS
Clean inside the front of the gas cylinder with the FLAT SIDE
Clean the piston grooves by scissoring
the SCRAPER around the grooves
Clean the front hole of the
piston with the FLAT SIDE
Leave M240 set
at #1 except in
emergencies
M249, M240 Machine Guns…
Gas
Problems?
SCrape ‘em
Away!
I think I have
carbon
congestion!
wHoo!
I feel
Awful!
what can I
do to hELP?
scRApe
it OFf!
Here’s how
to use the
scraper on
both machine
guns…
I CAN’T BUDGE
THis carbon
in your gas
system!
no wonder! you
waited
a week
to
clean it out. you
shoulda
cleaned
me right after
firing!
707 40-41.indd
1-2
9/12/11
10:23 AM
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