AR gas tube-clean, or?


March 26, 2014, 09:01 PM
I recently saw some posts on another site where someone asked whether or not you should clean the gas tube on an AR-15...some years ago, someone told me that keeping it clean was a must, but many replies to the guy's question were that it is not this true? I've only put about forty rounds through my AR, so it has not become an issue yet, but I would like to hear some opinions here on guy said he had shot thousands of rounds without cleaning it without problems, another said a gas tube only costs ten bucks, so just replace it if it becomes a problem.That sounded a little out there, but I'm new to the AR platform, having owned mini-14s, AK-47s and the L1A1 and don't know of any quirks yet with the AR...

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March 26, 2014, 10:15 PM
You're more likely to get something stuck in the gas tube trying to clean the inside than you are to do any good.

Keep the outside of the gas tube clean where the gas key covers it. Generally speaking, change gas tubes when you change barrels.


March 26, 2014, 11:06 PM
Yep, I'd say the gas tube typically has a longer service life than the barrel. Switch them out at the same time. If something does happen prematurely to the tube, I agree with replacing it rather than cleaning it.

March 26, 2014, 11:17 PM
They are self-cleaning when 12-14,000 PSI of hot gas blows them out every shot.

The only part of them that needs cleaning is the end that fits inside the gas key on the bolt carrier.

Wipe it off with a wet patch when you clean the rest of the rifle.


March 26, 2014, 11:21 PM
I use pipe cleaners on mine it works geat

March 26, 2014, 11:26 PM
Till you break one off in the gas tube.

I have a 44 year old Colt that doesn't know what a pipe cleaner is!

The risk outweighs any possible advantage.
Again, They are self-cleaning!


March 26, 2014, 11:44 PM
Thanks for the info, I'll keep the end of the tube clean and not worry about the rest of it...

March 27, 2014, 08:22 AM
I use pipe cleaners on mine it works geat

What do you mean by that?

I doubt you're removing anything that would shorten the life of the gas tube.


March 27, 2014, 09:18 AM
Now back in the way way back when I was an Army Small Arms Repairman we didn't cleaned over fouled gas tubes.
We simply replaced them.
Worse thing someone can do is shove a pipe cleaner into a gas tube.
All it does is shove the fouling into one huge mass somewhere around 5 inches up from the end of the tube and then the malfunctions would really begin.

March 27, 2014, 09:29 AM
I've been an AR owner since 1979, and I have never cleaned or replaced a gas tube in thousands of rounds fired. Keep your bolt and BCG cleaned and lubed and the barrel as well, and let the gas tube take care of its self. As the swamp people on TV say "choot it!"

March 27, 2014, 10:17 AM
I use the pipe cleaner on the outside of the tube not the inside sorry i was not clear about that

March 27, 2014, 10:20 AM
I'm really glad I read this thread. I'm fairly new to ARs, and I too have been running a long pipe-cleaner (soaked with Hoppe's #9) into the gas tube. I suppose it's a good thing that I've only run about 500 rounds through my new Windham. I won't be "poking the tube" anymore!

March 27, 2014, 10:48 AM
In the service I ran into M-16 A1 rifles with gas tube issues. Most common issue was a lime like scale build up that reduced flow to the point that ejection was sluggish and sometimes just not happening. This affected about one in five to one in four rifles in our arms room. Despite it not being a -10/20 user or unit maintenance issue in the service we initially cleared a few on the rifles using a mostly straightened out section of the wire from a spiral note book.

We did this to avoid having a rifle gone to Depot, charges to the unit, and a trooper without a rifle in the mean time.

We soon found a better job could be done with the tube off the rifle, using out new gas tube tool(that spiral notebook wire) followed by a king sized pipe cleaner.

It is my belief that the scale inside our gas tubes was build up from firing blanks with the BFA in place. I suppose it is possible that some of those rifles may have started getting crud stuck in them using the "bad" St Marks powder from the mid 1960's and the blanks debris just stuck better in those guns.....but I believe the issue was blanks and the use of the BFA on the rifle when using them. With the M-16 A1 MOST of the venting when using a BFA takes place at the breech, hard to believe but anyone that has cleaned the rifles after blank and BFA use and after only ball ammo use can see the difference in clean up. At night it is very obvious how much more fire escapes at the breech than through the BFA.

I do not believe this build up to be much of a problem, if at all, in rifles that never fire blanks with a BFA.

The fear that sticking "stuff" in the breech end of the gas tube getting stuck is real. I have seen rifles with pipe cleaners and match sticks, multiple tooth picks stuck in them and one guy using a worn out bore brush managed to screw it into the breach end good and solid.

If you want to know all the ways a GI can screw up a rifle, or the things that can go wrong with an AR-15, just hang around a unit arms room for a bit and you will see stuff. Actually one of my "best" M-16 A1 failures was when "Joe Snuffie" replaced a lost firing pin retaining pin with a bit of shaved down match stick. Firing pin came out the rear of the bolt carrier on firing, partially fell into the action of the lower, bent, thoroughly locked up the bolt carrier with it back enough to be partially in the recoil spring tube and caused me to have something of a blood pressure spike in finding out what happened when "It Just Quit!" That was also not a -10/20 repair.....but it got done.

Oh the other gas tube problem was bent or crimped along with crushed or broken old triangle hand guards. I think the tail gate of Duece-n-a-halfs or five tons were the main offenders here.

Still ya got to wonder how Snuffie got enough force on that part to crush a gas tube....


March 27, 2014, 11:09 AM
sheesh, kbob, that's funny stuff

March 27, 2014, 11:42 AM
I have a 44 year old Colt that doesn't know what a pipe cleaner is!

Thanks for info RC.

March 27, 2014, 11:49 AM
After I shoot corrosive 5.45x39 in my AR I flush the gas tube with water followed by some break parts cleaner to help it dry quickly.

I'll also usually flush some brake parts cleaner down the gas tube before switching back to 5.56 after using my .22lr conversion.

Otherwise I leave it as it as after cleaning the outside where it goes into the carrier key as has been mentioned.

Nom de Forum
March 27, 2014, 12:52 PM
........If you want to know all the ways a GI can screw up a rifle, or the things that can go wrong with an AR-15, just hang around a unit arms room for a bit and you will see stuff. -kBob

Roger that!

Two examples:

A Sergeant got angry and bored with having to pull guard duty on an FTX. To relieve the boredom he chambered a blank, removed the BFA, decrimped enough blanks to fill the barrel with powder, installed the BFA, and pulled the trigger. He was fortunate to be assigned to a DS unit that could replace the entire upper receiver assembly in the field without a record of it being done. He was 2 months from ETS and caught a break.

A Private used to playing games in the field shooting cleaning rod sections using blanks decides to see what happens when you use M193. The Private remained a Private until ETS.

I still have the remains of the sergeant's bolt carrier group and the sectioned barrel of the private's M16 showing the bullet and cleaning rod section lodged in the barrel.

March 27, 2014, 10:52 PM
Spray with. WD40. Never a problem with my M16A1 CARBINE using IMR4198 powder.

March 28, 2014, 01:14 AM
I use pipe cleaners on my gas tube as well. Only clean out the last 2 or 3 inches of the gas tube as rc said, they really are self cleaning until the gas starts to slow down and deposit. I am a clean freak when it comes to ARs so I clean every nook and cranny you could think of. At the end of my military AIT, we had two weeks to clean our rifles. Anyone who still had carbon in their rifle at the end of two weeks (found with a single white pipe cleaner) had to repeat BCT/AIT again.

Jorg Nysgerrig
March 28, 2014, 01:27 AM
Anyone who still had carbon in their rifle at the end of two weeks (found with a single white pipe cleaner) had to repeat BCT/AIT again.
And how many people repeated BCT and AIT?

March 28, 2014, 02:47 AM
And how many people repeated BCT and AIT?

One was recycled. Carbon buildup in the lower receiver from firing blanks likes to hide.

March 28, 2014, 03:31 AM
I use to spray gun scrubber down it.

March 28, 2014, 04:31 AM
In the Marine Corps infantry we were ridiculously anal about cleaning our M16s. We scrubbed the heck out of them. That perfectly clean rifle that herrwalther talked about? We usually only had a few hours to get our rifle that clean, not two weeks.

But we didn't clean the inside of our gas tubes. We weren't even allowed to. Why? Because it doesn't need it and you don't want anything to get in there. There's enough pressure and heat going through it that they're self-cleaning. Anyone who sprays something down their gas tube or sticks a pipe cleaner in there is simply wasting their time. And they might be clogging it up with gunk. Stop cleaning your gas tube and start worrying about the parts of your rifle that actually need cleaning.

March 29, 2014, 06:03 PM
Most people will never experience a clogged gas tube, but it is possible. This is from a torture test article where a gas tube clogged. It was a Bushmaster carbine using Brown Bear ammo.

The second half of the test started off with several malfunctions with the Brown Bear carbine – at 5,200 and 5,250 rounds, short stroking malfunctions were encountered. High speed video showed that the bolt was barely coming back far enough to pick up the next round, and occasionally not even far enough to eject the spent case. Additional lubrication did not prevent the second malfunction.

A detailed physical examination revealed previously unnoticed carbon buildup in the gas key and gas tube which had almost completely occluded those components. The other firearms were inspected, and none exhibited carbon buildup which was even remotely close to that of the Brown Bear carbine. Cleaning of these components in the field proved difficult to impossible, and it was decided to set them aside in order to examine the phenomenon.

So while it is possible, it is very unlikely. I shoot some carb cleaner down by gas tube when I clean my gun. Even if it might not be helping, it certainly isn't hurting either.

Bartholomew Roberts
March 29, 2014, 07:58 PM
Aside from recreational shooting and military use, my main experience with AR gas tubes was working for an FFL during college building ARs out of Bushmaster/PWA/Olympic lowers and Nesard parts kits.

I've read about several examples of gas tubes becoming clogged. If the powder used has a certain percentage of calcium carbonate in it, it can cause the problem. It is rare to see the problem nowadays since .223 is synonymous with the AR15 and few manufacturers use such powder. It apparently still happens occasionally with foreign surplus ammo though.

I can say that in 20+ years of playing with the AR15/M16, I've never seen a firsthand example of an AR that stopped running due to a dirty gas tube. I have, however, seen dozens upon dozens of ARs with stuff jammed in the gas tube from "cleaning".

Since replacing the gas tube is a single pin punched out and a $10 part, I tend to replace the gas tube with the barrel and not stick anything into it. I do run a pipe cleaner through the gas key to verify it is clear ever since I had a particularly tricky problem with a popped primer wedged in the gas key.

March 29, 2014, 10:23 PM
If you simply MUST clean it, use the straw and shoot some wd40 in the tube. Give plenty time to soak (20 minutes?), then chase it with some cheap ($2) carburetor cleaner from from the automotive section at walmart. Again using the straw. Then clean the barrel.

I only do this if I intend to store mine long term.

March 30, 2014, 09:16 AM
Gunsmiths love pipe cleaners. They get to charge you for a new gas tube and its installation.

March 30, 2014, 05:42 PM
I have seen one plugged gas tube. It was on an sbr, with a pigtail tube, that the owner had been running a .22lr conversion kit on. After about a brick and a half, it wouldn't cycle 5.56. He sprayed brake cleaner in it, and some got left behind in the loops of the tube. Started a fire when he tried to shoot it the next time.

He only had to replace the gas tube, IIRC.

March 31, 2014, 12:27 AM
I have never broken off pieces of pipe cleaner inside the gas tube. I have seen it happen only once, and that person was a special kind of special. Every time I clean the gas tube, carbon residue always comes out. I never use any solvents or sprays because that will cause more problems than the carbon build up. I think gas tube cleaning is more crucial if you shoot blanks more than live ammo, which the military does frequently.

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