AR Pistol FTE problem

[RANGER295]

I built an AR pistol with a 7.5 inch barrel. The lower is factory as are all of the upper parts but I put the upper together from parts picked up here and there over a couple years. I was worried about not having enough gas pressure to cycle the weapon so I put a Krinkov muzzle booster on it to boost the gas pressure.

It feeds and fires fine, but almost every round fails to fully eject. The empty casing disengages from the bolt/extractor but ends up jammed between the right edge of the bolt and the edge of the chamber. Usually there is a live round that is partially out of the magazine jammed in there as well. It is almost like a stovepipe except the empty is facing forward not sticking out sideways.

I know for a fact that the issue is the upper. I put the upper on a friend's AR pistol lower and had the same problem. I was wondering if it was a weak extractor so I threw the BCG in two rifles and one pistol and had no problems. I am thinking this has something to do with gas pressures. I have tried several types of magazines ranging from P-Mags to pinned USGI and three types of ammo (Winchester, Brown Bear, and Wolf) and had the same results with all. Does anyone have any ideas? Thanks in advance.

[Devilmonkey89]

Most if not all AR pistols are overgassed. Check your brass for ejector smears and go from there.

[RANGER295]

Most if not all AR pistols are overgassed. Check your brass for ejector smears and go from there.

I will have to go out to the shop and look at the brass. Maybe I should not have put the muzzle booster on it.

[Bridger2cmu]

I had the same problem on mine. I replaced the gas block with an adjustable one and it's been running like a champ since. After my build I would say that 10.5" carbine gas system is as short as you should go.

On my 7.5" I tried replacing buffer springs, buffers, AR bolt carriers, M16 bolt carriers, and it wasn't until the gas block that things started working. Yes, it's just too much gas that is ripping the bolt carrier back too soon.

[EBR Works]

We have built hundreds of AR pistols. These generally fix this issue:

http://www.amazon.com/5-56-Extractor-O-ring-Crane-pack/dp/B00IEIU9VK

If you just need one, send me a self addressed stamped envelope and I'll send you one. PM me to get our mailing address.

[mobbology]

We have built hundreds of AR pistols. These generally fix this issue:

http://www.amazon.com/5-56-Extractor-O-ring-Crane-pack/dp/B00IEIU9VK

If you just need one, send me a self addressed stamped envelope and I'll send you one. PM me to get our mailing address.

Yup!!!! Take this guys offer. Worked for me

[ihasacookie]

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm

Might also want to take a look at the extractor spring too. BCM makes a kit with the same O ring with a beefier spring.

[BullseyePursuit]

I was having the same issue but for me, I had to replace the bcg. I also fully lubricated the upper receiver then it worked fine

[EBR Works]

I guess the OP worked it out. He did not contact me...

[RANGER295]

I guess the OP worked it out. He did not contact me...

Sorry, between a new baby at home and getting slammed at work today partially because of being gone most of last week due to the new baby I have just not had a chance to get back online. I have not even had a chance to go look at the brass.

[cdtx2001]

How do the rounds extract manually?

[EBR Works]

Sorry, between a new baby at home and getting slammed at work today partially because of being gone most of last week due to the new baby I have just not had a chance to get back online. I have not even had a chance to go look at the brass.

Congrats on the new addition! PM sent.

[RANGER295]

Congrats on the new addition! PM sent.

Thank you. He is a bundle of joy. Should I take off that muzzle booster and put something else on there?

How do the rounds extract manually?

They do not because they disengage the extractor and lodge between the edge of the bolt face and the edge of the chamber. You have to drop the mag and pull the charge handle and the empty falls out the magwell. Sometimes a live round is jammed in there too.

[RANGER295]

I went out to my shop an played with the pistol a little. I took the muzzle booster off and still had the same problem. I took the mag out and loaded single rounds. They ejected fine. The brass had the ejector smears that that you talked about.