Stuck case ETA". Gas tube installed backwards

[mike28w]

Hi ! Grendel newby here.

I just finished assembling an AR with 12" Faxon barrel and went to the range today. Shot factory Hornady ammo... 1st round failed to eject . Stuck completely in chamber. I was able to eject the round by pulling on the charging handle, very hard, with both hands while resting the butt on the pickup tailgate. 2nd round....same exact results.. 3rd round....tried a steel cased Wolf cartridge just to make a random change. Same results except that it was not possible to remove empty case by hand.

Had to take it home and using a fiberglass rod , had to pound quite hard on it to get the case out.

All 3 cases look fairly "normal" . No splitting, no separations, no unusual bulging near the base. Primers are a little flat but not backed out.

Both before and after firing ....the bolt could easily be moved forward into the lugs by a couple of fingers and then easily moved back by just a couple of fingers. There's no catching, rubbing or friction. Everything is smooth. Normal amount of lube.

I am able to easily insert a round by hand by simply tipping the barrel down and the round slides in. I can also tip the barrel up and the round easily slides out.

So , my question is ....what to do now ??? Any suggestions would be greatly appreciated !! Thanks, mike

[VASCAR2]

Make sure the gas block is centered over the gas port, also make sure the gas tube is alligned with the carrier. If you have access to an air compress you can blow air into the muzzle and see if the gas system is open. Did you liberally lube the bolt and carrier and clean the barrel and chamber prior to test firing?

I’d also use a black marker to color the nose of the bullets to ensure the bullets are not into the lands of the barrel. What buffer tube are you using, pistol or carbine? What buffer spring and buffer did you try.

[mike28w]

Hi, Thanks for the good ideas !

I'm fairly sure that the gas block is over the port. I measured it pretty carefully. Bolt and carrier were clean and lubed. Carbine buffer tube with standard spring and H2 buffer and adjustable gas port. I don't "think" it's the spring or gas system because the empty case gets stuck. I struggled to even get the charging handle to move .

I will be trying the black marker idea but am hesitant to close that bolt again for fear that it will lock up on me again........it was a job to pound out the empty and I'd really rather not be pounding on a loaded round...

[Drillboss]

Fired brass is bigger than unfired brass. Bump the buttstock down onto something while pulling back on the charging handle.

If it was me, I'd load a single round in the mag, (set safety to Safe, point the muzzle in a safe direction) release the bolt carrier, and then see if the round extracts easily. If not, you may have a headspace issue or possible a tight chamber somewhere behind the shoulder. I just worked through the latter problem.

Like Vascar indicated, I've heard of similar problems with adjustable gas blocks that are closed off.

[98Z]

We know the barrel (stated), but what bolt carrier and bolt are you using?...

[Klem]

Sounds like your gas port is closed.

The only time I have experienced sticky-ejection like yours is when the adjustable gas is completely closed. The AR needs a bit of force on the BCG to unlock it and free the case. I would suggest having a good look at the gas system. The port might still be closed even though you've cranked it open with an Allen key.

[GregP42]

And one thing I have seen done and never figured out how they did it, gas tube was upside down in block....

[Crusty]

I use a short length of automotive vacuum hose which pushes onto and seals on the end of the gas tube in the receiver. If I can easily blow through it and hear hissing in the barrel then I know my gas system is unblocked.

[bigdaddyflo]

We know the barrel (stated), but what bolt carrier and bolt are you using?...

This could be the problem - are you certain you have the correct bolt for the chamber? Group buys here typically require the .136" bolt (Type II).

Type I - .125"
Type II - .136"

[mike28w]

Well...with a little trepidation, I just loaded a single Hornady round and hit the bolt release and the bolt closed like it should. Then pulled on the charging handle and the round ejected easily , in a normal fashion. Then repeated it with Wolf ammo with the same good results.

I blackened a round and inserted it and closed the bolt with the bolt release. Easily ejected and found no rifling marks on the bullet.

Measured the bolt face and got .136" to .137"....

I'm beginning to wonder if this is a matter of too much headspace ??? When I assembled everything, , I couldn't find any company that actually had a headspace gauge in stock...they were all back-ordered. (No re-stock date listed.) I "rednecked" it with "plasti-gauge" and came up with a headspace measurement of .006 "

I very much appreciate everyone's time....please keep the suggestions coming !!

[bj139]

I have posted this before so here I go again.
Clean your chamber with solvent and a 45 caliber brass brush.
Sometimes there is some dried gunk from the reaming process.
Wrap a small piece of paper towel or a cleaning patch on the brush and add some solvent until it comes out clean.
Then dry it and you might be GTG.
If it doesn't help then I was wrong.

Wolf steel cased ammo does stick more than brass ammo.
I do a lot of manual ejection so I know.

[mike28w]

Thanks, it came out clean.......

[Popeye212]

You mentioned adjustable gas block I think I would be looking there and for positioning. If it cycles fine and the bolt ejects and locks properly.

[mike28w]

UPDATE !! Well...I figured that I may as well just tear it all apart and check everything. I took off the gas block and tried to blow through it ....No Go !! A ha ! Took the block all apart and found that the gas tube had been installed upside down.....

I had a shop install the barrel ( didn't have a proper wrench) and since I was buying a gas block from them...they installed the gas block too..... There is the culprit !! So I just finished reinstalling the gas tube....I can blow through it ! Installed the gas block on the barrel , everything seems smooth.

Going to shoot it after a little lunch !! Report to follow !!

[mdewitt71]

And one thing I have seen done and never figured out how they did it, gas tube was upside down in block....

I just did this on a 20" AR build....... freaked me out, never had it happen before.
It fired just as the OP has stated and I took the hand guard off to realize what I had done.
I have build thousands... and I really mean thousands as my DOD team just rebuilt 5,500 M4s for the Army MP school this winter.
That is what I get for hurrying and wanted to take the rifle out on my day off haha.

[ClutchAutomatic]

Rookie mistakes

[mdewitt71]

Rookie mistakes

I dont know about Rookie...
I am paid to R&D and build weapons by the thousands sometimes so, one would say that is a profession ha-ha and I still aint perfect.

[GregP42]

I need to mark on the calendar that I was right, no one in my family would belive me :o

[mike28w]

Well, I got back from shooting the Grendel. Cycles fine !! Ejects everything. Too cold and windy to sight it in but I'm a happy camper. I really think it's going to be a neat little AR.

I want to thank everyone for their time and input.....I was becoming more and more convinced that I'd have to find a gunsmith....

Thanks, again !! mike

[bj139]

I alway look to make sure the hole in the gas tube is facing down. But what do I know?