View Full Version : AR Pistol Issue

04-10-2012, 12:15 PM
So since I had so many spare parts lying around....I picked up a cheap pistol upper at the gun show. 7.5" Barrel. Put the gun together and went to shoot it Sunday. It would fire once, pull the trigger the second time and click. But no round had chambered. Rack it....fire once....pull the trigger again....click. No round. Did this 25-30 times in a row.

Tips on what to check for first? It does it consistently, I couldn't get it to fire twice in a row. Using Winchester ammo. Mag works well in my other AR's and AR pistol. I'm running GSE buffer / bolts in both my pistols, next time I'll swap em out to confirm it that's the problem....just kinda hoping the whole bang/click thing is a clue to what's going on.

04-10-2012, 1:01 PM
was the upper completely assembled or did you do it yourself? There are two lengths of pistol gas tubes, one for the 7" and one for the 7.5".If you have the wrong length gas tube( too short) a lot of the gas will exit through the side and not push the bolt carrier far enough back to cycle another round. Or you could not be getting enough back pressure to cycle.

04-10-2012, 1:03 PM
It was assembled. The gas tube as the issue has occurred to me...just not quite sure how to confirm if it's the problem or not.

04-10-2012, 1:23 PM
Sounds like something with gas system. The gas key of your bolt should make contact within the gas tube.
This is general pic of how much gas tube should be sticking into the upper receiver


You can see this happening if you shine a light and slowly lock the bolt in.

If the gas tube seems to correct length then either the gas tube is plugged/blocked or not correctly installed on gas block.

AK all day
04-10-2012, 1:26 PM
Sounds like a gas system issue, when it goes click is actually grabbing another round out of the magazine? Is it ejecting the casing? Do you notice any carbon flying out of unusual places?

AK all day
04-10-2012, 1:28 PM
Scratch the grabbing round part. Sorry.

04-10-2012, 3:20 PM
Cool, that's a good start...I'll take a look tonight and post what I find. Thanks!

Dark Sky Solutions
04-10-2012, 3:26 PM
Timing might also be your issue. the 7" barrels do sometimes have problems depending on how big your gas port is and the OAL of the gas tube.

Good luck fixing it. Personally if I am going to build up a pistol, the shortest I go is a 10.5" to make my life easier.