Gunsmithing Remove Blockage from AR15 Gas Tube

[rideHPD]

In my infinite wisdom I broke a chip of a wooden dowel off into the gas tube while trying to half-assedly unseat my gas block. Really took the bubba-smithing to the max on this one. The only things I can think of are plugging the breech and chamber and blowing it out with compressed air or trying to get a very narrow wood screw to screw into the piece and pull out. Any other ideas? Too deep in for tweezers. I imagine that trying to simply let it be shot out from a discharging a round would push the pressure through the roof, taking that option away.

 

[MarinePMI]

I guess it depends where in the gas tube the debris is stuck; a long pipe cleaner might work (from Michaels craft supply store). The other option is something that dissolves wood/celulose like Lye or some other acidic type liquid that won't harm the metal.

Then again, a gas tube is somewhere around $15...might be worth the headache just to order another one...

BTW, if it is blocking the gas tube, it won't raise pressures significantly if you shoot the rifle; it just won't cycle. It'd be the same as shooting it in a bolt action rifle...

 

[RHunter]

^^^^^ What he said^^^^^^

 

[rideHPD]

Tried the lye, so far it just went right past it and out the muzzle (hope there's nothing bad that's going to do). Wood still is lodged in there it seems, only deeper now when I tried to probe it.

I thought of a new gas tube, but I can't get the block more than a mm or two past the journal, and I can't really tap the block off directly because the rail is somewhat stuck on as the screws bolting it to the barrel nut were cross threaded bc the threads on the receiver were slightly out of spec and the barrel nut wasn't threaded far enough in. Cascading idiocy is reigning supreme right now, I know. I'm thinking that once the lye sits for a bit try to blow it out with comp air, unless there is a better idea. Has anyone ever tried blowing it out with a round? Any one have a good understanding of that that suggests it might ka-boom? It seems that if it's fine with the gas block closed off (port plugged/adj block switched off) it could handle the pressure from this, but would there be any side effect to the BCG?

 

[bptactical]

Got an old bicycle around? Take the inner cable from a derailluer or brake cable, cut it to length and roto-rooter the tube. Use low drill speed and make sure the rotation of the cable is such to "unwind" the cable. The cable won't damage the tube but it should nibble the chunk of wood ok.

 

[rideHPD]

I've met some talented engineers, but that is absolutely brilliant. I didn't even think there would be any good way to get it out the other end.

 

[smokebomb]

Ride...you're an engineer?

Can you not remove the roll pin from the gas block and completely remove the gas tube?

What model gas block are you dealing with?

What model quad rail are you dealing with?

I ask these questions to get an idea of which ones gotta give to accomplish your task...if you have a pseudo non-removable gas block and a stripped out quad rail.

Soak your gas block in hoppes black powder solvent or kroil or the like for a day or 2. Plan on replacing the gas tube, and use it and a non-marring punch from the bottom of the gas block to convince the block off. Then replace those stripped screws on your quad rail. C'mon engineer

 

[338RUM runner]

Get a Torch and burn it out, they do get red hot on full auto and seem to work OK after. Never hurt mine and I got it red more than a few times.

 

[sgtsmmiii]

Dental pick?

 

[rideHPD]

Tried the torch, actually Randall from AR15Barrels.com did, and we decided to stop as it wasn't necessary (we were trying to re-time the SF brake on the rifle). The problem isn't with stripped screws, but that they've tapped (threaded tapped) the barrel nut on one side. As such the nut and rail are essentially cold-welded together. Wasn't planning on messing with it unless it was really necessary.

Soaked the GB in brake cleaner overnight, and heated, didn't want to budge too much. It moves, but doesn't want to go too far, I think there just might be a burr from one of the set screws that's impeding it, not carbon buildup.

But alas, I solved it earlier. The lye helped break it down, after I attached some rubber hosing to it, poured in some carbon solvent (reduce wall friction from carbon buildup and try to remove some carbon that could hold ions) and used a little hydraulic pressure from a big syringe and blew it out. Cleared it out into the barrel, ran some vinegar through it (neutralize the lye), couple runs of water to get anything else out, then penetrating oil into the gas block to get any water out to avoid crevice corrosion, blown dry with comp air from computer duster can, then cleaned the barrel as usual. Flow is same with other rifle length gas and similar block, should be all good to go.

 

[338RUM runner]

Note to Self, don't try that at home. Glad all is well.

 

[Wintermute]

Get a Torch and burn it out, they do get red hot on full auto and seem to work OK after. Never hurt mine and I got it red more than a few times.

Beat me to it. It's wood trapped in metal...metal that will often get searing hot while firing the gun. Just heat the tube up enough to burn the wood out.

--Wintermute

 

[rideHPD]

Note to Self, don't try that at home. Glad all is well.

Seriously, that was pretty damn stupid and lazy.

 

[Decoy]

You might try termites.com if all else fails

seriously any any small wire like below should do the job in a small drill.

 

[peligro113]

buy a new one for $10 save yourself the grief