AR Pistol Not Cycling

[303hunter]

Im working on an AR pistol that’s not going fully into battery for the second round in the magazine. It chambers fine with the charging handle, and will empty a magazine when done manually. It won’t quite chamber the second round after the first is fired though, it stops just short of being fully chambered. Sometimes the second round will chamber with the forward assist, sometimes not. First thing I did was polish the chamber and extension, with no improvement.

I’ve tried different mags and BCG, and have taken the whole upper apart and checked torque values, made sure gas block is aligned, and even tried a different buffer and spring. The barrel is a PSA 10 1/2” 5.56. It ejects to 2:30, so it’s a bit over gassed. I’m stumped, any ideas?

 

[Geezer]

My rifle did the same thing. It would fire a round but would not go fully into battery on the next round. We tried all kinds of magazines, same thing. It turned out to be the ammo. I was running steel cased Wolf. My other AR loves the stuff, so I never dreamed it would be the ammo. We tried everything that we could think of and when we ran out if ideas I suggested trying brass ammo. It ran like poop through a goose.

 

[303hunter]

I haven’t tried steel cased ammo, only m855, m193, and my reloads.

 

[NKD]

Were the other spring and buffer the same weight?

 

[bigfelipe]

Light/weak buffer spring? Doesn't make sense to be weak ammo if it's over-gassed.

EDIT: does it do it with all the ammo you listed or your reloads? I would take them out of the equation for now.

 

[Short Fuse]

Pics and parts list please.

 

[SDIVER2006]

I had the exact same issue
1:8 .223 Wylde 10.5 in barrel
I swapped out the gas block got an adjustable one I have the slr sentry

My problem solved...

 

[1911gobang]

Upgrade the bolt, O rings, and extractor, heavy buffer and spring. Mine ran like shit through a goose after that...


Sent from my iPhone using Tapatalk

 

[Butter]

I had the exact same issue
1:8 .223 Wylde 10.5 in barrel
I swapped out the gas block got an adjustable one I have the slr sentry

My problem solved...

Gas block my guess as well. My rifle would short cycle with my reloads, but ran fine with factory loads. Put an adjustable GB on and now it runs like a top.

 

[303hunter]

Were the other spring and buffer the same weight?

Buffer that came in it was a H. I tried a standard buffer with same results. Spring is standard carbine. Also tried another spring with same results.

 

[303hunter]

Light/weak buffer spring? Doesn't make sense to be weak ammo if it's over-gassed.

EDIT: does it do it with all the ammo you listed or your reloads? I would take them out of the equation for now.

Does the same with all ammo.

 

[NKD]

Buffer that came in it was a H. I tried a standard buffer with same results. Spring is standard carbine. Also tried another spring with same results.

Hmm. Still sounds undergassed.
Is it possible the case is being drug into the deflector on extraction which sends it forward, and that is what is causing it to go forward of the ejection port? A person with an iphone on slomo might help to clear this up.

Not an expert, just throwing out ideas.

 

[303hunter]

Upgrade the bolt, O rings, and extractor, heavy buffer and spring. Mine ran like shit through a goose after that...


Sent from my iPhone using Tapatalk

Tried my Toolcraft NIB BCG with no improvement. It's been a good unit in a couple builds.

 

[303hunter]

Hmm. Still sounds undergassed.
Is it possible the case is being drug into the deflector on extraction which sends it forward, and that is what is causing it to go forward of the ejection port? A person with an iphone on slomo might help to clear this up.

Not an expert, just throwing out ideas.

Cases not hitting deflector, just way over gassed. Called my buddy John at Shooters Supply, and he said to try an H3 buffer to slow the cycling rate down. It worked- sort of. Rifle went into battery, but wouldn’t fire second round. Trigger felt like it was on safety, but wasn’t. Pulled the trigger twice more and it fired again. Trigger didn’t feel right.

Took it home and took the trigger out. It seemed to be installed properly, but I put in another trigger group. Went outside and dumped 2 mags, so it’s running now. Only thing I can guess is an out of spec trigger group. I had an Anderson trigger once that the safety wouldn’t work on at all, so I guess stuff happens.

 

[NKD]

Cases not hitting deflector, just way over gassed. Called my buddy John at Shooters Supply, and he said to try an H3 buffer to slow the cycling rate down. It worked- sort of. Rifle went into battery, but wouldn’t fire second round. Trigger felt like it was on safety, but wasn’t. Pulled the trigger twice more and it fired again. Trigger didn’t feel right.

Took it home and took the trigger out. It seemed to be installed properly, but I put in another trigger group. Went outside and dumped 2 mags, so it’s running now. Only thing I can guess is an out of spec trigger group. I had an Anderson trigger once that the safety wouldn’t work on at all, so I guess stuff happens.

Glad you got it figured out!