Powder Blast and a pneumatic air hose set at around 60psi
Shoot the PB into the tube, wait 5 minutes then blow out the gas tube. Clean the bore in the normal manner.
joat
I spray CLP in in, let it soak; then drain out any build up. Afterwards it goes right back to the range. I have repeated this without any failures yet.
With the pressures invloved in the gas tube, and the fact it's made from stainless steel, you shouldn't have to worry about any kind of fouling or build up in the gas tube itself. I never clean the gas tube, but always use a Q-tip to clean the gas key on the bolt...
I really don’t know if the tube needs to be cleaned, but given that I like clean guns, I will run a pipe cleaner down the tube.
I do think you will get 99% of the crud out with pressurized brake cleaner. Just clean the barrel later.
If you do use a pipe cleaner, buy a medical forceps. You will stick the pipe cleaner so deep in the gas tube that you won’t be able to grab the end with your fingers. A medical forceps will save the day.
I also don't think the gas tube needs cleaning, and attempts to do so with pipe cleaners, etc. can clog it up. There are examples of ARs with 40,000 rounds and the gas tube never has been touched (BCM's filthy 14 for one).
Now if you fire a lot through a .22LR conversion unit the gas tube and gas port can get horribly fouled.
A long pipe cleaner works well. I don't let my gun go years on end without cleaning so some CLP and wipe it till it's dry with pipe cleaners works well.
I don't ever clean it. Seriously, it's a $12 part that takes 30 seconds to swap out. It regularly has high temp and pressure through it, and that will blow out any junk.
From what I've read, you're more likely to ruin the gas tube than do anything productive. If it bothers you that much, just get another; it's no more expensive than two magazines worth of ammo.
DO NOT PUT ANYTHING IN THE GAS TUBE.
All you'll do is get something stuck there, or block the tube.
The gas tube is totally self-cleaning.
The super heated incandescent gas under tremendous pressure coming down the tube burns out or blows out any possible fouling.
Any liquid you put in the tube will instantly carbonize to a sticky tar-like substance that can reduce gas flow if the pressure can't blow it out, which by the way is blown into your bolt carrier causing it to foul.
Put anything in the gas tube in the military and your Sergeant will have your A*S on a plater.
If you have ANY problems with a gas tube, you simply replace it. They're cheap and easy to replace.
Gunsmiths just LOVE people who "clean out" their gas tubes. We make good money replacing them after the customer gets a pipe cleaner stuck or broken off.
Whoever decided to sell "special" gas tube cleaning pipe cleaners should be shot.