View Full Version : Gas tube cleaning on an AR...?

November 9, 2012, 02:27 PM
HI folks,

Following up on my recent purchase of a S&W M&P 15 Sport, what is the maintenance interval and type(s) of cleaning methods to clean the gas impingement tube?

How do I tell when it needs cleaning - besides when the bolt won't cycle?

Does cleaning require removal of the front A2 sight? If so, does this mess up the zero? Maybe a lame question, but I haven't had that part off the gun yet.

I learned when I was 6 that I can only disassemble an alarm clock so many times (once) before it won't work any more. Trying not to do that to my firearms.... :rolleyes:

Willie Lowman
November 9, 2012, 03:23 PM

Willie Lowman
November 9, 2012, 03:28 PM

Anyone that says you have to clean that tube is full of it.

November 9, 2012, 03:35 PM
I agree with Mr Lowman. A couple of years ago, paging through the Midway flyer, I saw the gas tube pipe cleaners. I think, my AR probably needs it. I'd had it for 10-12 yrs, shot thousands of rounds etc. The gas tube MUST be dirty. Got the pipe cleaners, ran one thru, and was thoroughly underwhelmed by the amount of carbon that came out. I wouldn't sweat it.

November 9, 2012, 03:37 PM
Thanks, all....

MyLGS sold them in bags of about 100 or so. I got SCARED that is was a daily ritual, or something you did if you left a box of Wolf ammo laying too close to your gun, or something....

November 9, 2012, 03:41 PM
I've never shot Russian ammunition through mine, but like the poster above you, the few times I've run anything down the gas tube it was perfectly clean.

I'd leave the gas tube alone. You're more likely to have something get stuck in it than improve its performance by cleaning it.

Crow Hunter
November 9, 2012, 03:49 PM
Pipe cleaners are good for cleaning out the firing pin channel and knocking the carbon out of the gas key turn. Not something that you have to do all the time but it doesn't hurt anything. (DO NOT TRY TO THIS WITH A Q-TIP)

Don't put anything in the actual stainless steel gas tube though. If something ever stops it up, just replace it.

November 9, 2012, 04:20 PM
I get a little worried about the longevity of my S&W AR-15, gas tube, because I shoot corrosive 5.45X39 ammo. So far... when cleaning the rifle, I've been spraying inside the gas tube, with high pressure brake cleaner fluid; and letting it drain out. So far...no ill effects, on my gas tube.

November 9, 2012, 04:29 PM
I don't really think it is necessary but I occasionally shoot a squirt of brake cleaner down the tube with the barrel pointed down. Maybe not necessary but I like to clean things up a bit. I certainly doesn't hurt anything.

Sorry Erno, just read your post.

November 9, 2012, 05:10 PM
I'm with the "never" crowd. The only reason it might possibly need any attention at all would be if you shot a whole bunch of .22LR through a conversion kit. However, the conversion kit makers recommend you swap it out and fire a few full power rounds every couple magazines. Reason being, the high pressure from the gas on a .223 round will blow the junk out of there.

If you're going to shoot THAT much .22 through a conversion kit, just get a cheap gas tube, cut it off, and install it in the gas block upside down. Then swap back with a normal tube when you want to go back to rifle rounds. Spike's sells a small tube blank for this purpose, but it costs as much as a normal tube anyway.

If it ever gets clogged, it's a replacement item, not something to clean.

November 9, 2012, 05:16 PM
How about carburetor cleaner?

November 9, 2012, 05:52 PM
Aerosol cleaners?
more likely to drop the straw down the tube. I am fairly certain a rifle round develops more pressure than a spray can and the solvents tend to spray gunk to a different spot rather than dissolve anything

November 9, 2012, 06:15 PM
Been shooting AR's for over 30 years and have never cleaned the gas tube. Not saying it doesn't need it. For all I know it take 31 years to get dirty.

Crow Hunter
November 9, 2012, 07:16 PM
Been shooting AR's for over 30 years and have never cleaned the gas tube. Not saying it doesn't need it. For all I know it take 31 years to get dirty.


That's good. I like that.

November 9, 2012, 07:58 PM
You are more likely to mess up a gas tube by cleaning it. It's virtually self cleaning with the heat and pressure that goes through it.

November 9, 2012, 08:38 PM
OK... I'm selling my pipe-cleaner stock!

November 10, 2012, 09:11 AM
OK... I'm selling my pipe-cleaner stock!

i'll give you a http://www.usmint.gov/mint_programs/info/images/2012_nickel_unc_obv_200.jpg for all of it. :D ;)

November 10, 2012, 11:59 AM
Done! I only paid a PLUG nickel for it!

chris in va
November 10, 2012, 07:17 PM
I'm surprised 5.45 is corrosive. Didn't they do away with that type of primer 40 years ago?

November 10, 2012, 08:36 PM
Military surplus 5.45x39 ammo is still corrosive.
The Russians decided it lasted longer in storage and works more reliably in extremely cold conditions.

The commercial ammo is non corrosive.

As for as flushing out an AR gas tube shot with corrosive ammo, carb cleaner has no effect on the corrosive salts. If you want to flush the tube, use water.

As far as cleaning a standard AR gas tube, you have super heated incandescent gas at 2000 degrees and 20,000 PSI coming down the tube. What's going to resist that that could be cleaned out with anything?
If you have a gas tube problem, you replace it.

I talked to my buddy today, who's a Match shooter. He says one of the men in his club has an AR with over 8,000 rounds through the same barrel and gas tube, with no problems and it's still accurate.

In the military, get caught sticking or spraying anything in a gas tube and your Sergeant will stick something up your gas tube.

November 10, 2012, 08:59 PM
I attended a Colt taught, M16 armorers class 5-6 years ago and the instructor made the statement that the gas tube was "essentially self cleaning".

I found that hard to believe, but do not clean mine, nor do I know anybody that shoots AR's, that does.

November 10, 2012, 09:06 PM
Thousands of Wolf and Tula and no issues cycling.