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How to clean heavy carbon buildup? Chisel or grinder?

3726 Views 11 Replies 12 Participants Last post by  DSM
The gas valve and piston tend to get a heavy carbon buildup on my XCR. What is the best way to clean this stuff? Normal cleaning with Hoppes 9 works, but it takes awhile.

I've also noticed that the gas tube will dump some of this carbon on the barrel and you will get a buildup on several spots there too.

I've been tempted to try something else, like carburetor cleaner. :raspberry:
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I use dental picks to get the worst off.
I bought a Shotgun. Tornado brush and used it to clean the tough carbon from
inside the gas tube.

I use gun scrubber and hoppes # 9

Known as "The Gunsmith's Brush", the Tornado brush has a special spiral-wound design that's highly effective for cleaning bores. The stainless steel loops eliminate any bristle ends that could leave scratches, yet removes fouling without damaging bore.
I use a paper towel, and just wipe it off.

Here's the deal..... get on the Brownells website, and order some SLIP2000 'carbon killer'. It's a green liquid, comes in a plastic quart sized container. Kind of smells like oranges.

Take the parts you want to 'carbon kill' and drop them in the goop for about 5 minutes. Pull 'em out and wipe the carbon off with a paper towel. BE WARNED HOWEVER: carbon killer takes off ALL the oil - you gotta oil it afterwords or the parts will rust. This works tremendously with things like AR15 bolt carriers and bolts - for oil I hose 'em down with Birchwood Casey Sheath (the aerosol gets into all the little cracks and such) then wipe off the excess with a towel.

For parts that are too big to stick in the carbon killer (like the gas piston) I've got a two-step process. First, get the majority out with a drill bit like I do with my M14 gas pistons. Then Hoppes Elite gun cleaner (the squirt-pump) will work the rest out FAST. Not as fast as the carbon killer, but quick.

For a lubricant, get a quart of Mobil 1 synthetic oil. The whole purpose of that oil is to keep carbon in solution so it can be filtered out (reduces carbon deposits in engines). It smokes a bit at first, but on things like AR15 bolts, unless the oil dries out - more like migrates away - the carbon can be wiped off.

I got 'clued in' on the Carbon Killer by the armorer at Gunsite, the Mobil 1 from the Navy's National Match armorer, the Hoppes Elite from a barrel maker. They all work.

Hope that helps!
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If carbon is REALLY bad, I just soak the offending piece in good old Hoppe's #9 for a day or two. Usually wipes right off then. I haven't bothered to clean my XCR's gas system yet (might be a candidate at this rate), but that's my usual strategy for my AUG or my P7's gas pistons.

It works.
I find a jackhammer works quite well... ;) ;D
Militec is an alternative to Mobil 1 as posted by Bravo.

It is also synthetic and works extremely well. Ease of cleanup is equal to Mobil 1's outstanding properties - but I do not notice the "smoke" as experienced with Mobil 1.
Additional questions: should the goal be to get the gas system-related parts 'shiny'? Do folks use a barrel brush on these parts, after soaking in something like carbon killer?

I too have used small picks on the gas dial and holes. I've not ever taken the gas block off of the barrel (about 4000 rounds so far in my XCR). I'm just not sure how clean these parts should be. I shoot a lot of Wolf, that stuff is filthy. But that's why I have an XCR, so I can run anything.

What is reasonable cleaning vs. OCD/Howard Hughes endless germ phobia insanity cleaning? :)

BTW, I recently had the opportunity to run a Bravo Company carbine with over 20K rounds through it, never been cleaned. Only SLIP 2000 applied liberally. Ran like a dream.
This may be a stupid question :

but why not use carberator cleaner ?

Me and my friends all use mobil 1
A wire brush in the grinding wheel takes off everything, even that pesky parkerizing. ;D
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