AR15 short stroking?

[Domingo]

I took mine new ar to the range, and was firing a round, ejecting but not loading the next round also did not lock the bolt back on the last round.
I been researching and all I come out with that the riffle is under gas or weak ammo. the empties were landing about 5 feet away at about 3 O'clock. the ammo I was using was some of my reloads so it could have been them. (they have cycle my S&W ar15 fine).I'm going to head back later on the week and try some factory ammo.
If the gun is over gas, could that cause failure to lock back. or is it more under gas.
the riffle
is Aero lower
upper PSA carbine gas 16" barrel

[m16]

Lube it up and keep shooting it, maybe try a lighter buffer.

[Domingo]

its got a carbine buffer 3oz

[kcheung2]

what's the charge on your reloads?

[TruEdge]

Adjustable gas block should also do the trick.

[Tac driver]

what's the charge on your reloads?

This.......more specifically what is your exact load data? Though a carbine gassed 16" barrel should have enough dwell to cycle a wide variety of ammo. Possible gas block miss alignment issue?

[Tac driver]

Oh wait it's a psa upper and they never mess up!

[Domingo]

What's the size of the gas hole on the barrel should be?

[Mail Clerk]

I took mine new ar to the range, and was firing a round, ejecting but not loading the next round also did not lock the bolt back on the last round.
I been researching and all I come out with that the riffle is under gas or weak ammo. the empties were landing about 5 feet away at about 3 O'clock. the ammo I was using was some of my reloads so it could have been them. (they have cycle my S&W ar15 fine).I'm going to head back later on the week and try some factory ammo.
If the gun is over gas, could that cause failure to lock back. or is it more under gas.
the riffle
is Aero lower
upper PSA carbine gas 16" barrel

Domingo,

I had the same issue with one of my AR's and out of disgust I swaped out the entire BCG assembly for another and it began to work properly! My guess is that the bolt portion isn't locking up fully in battery. Try that route and see what happens.

Mail Clerk

[rdmax]

I had a no name brand buffer tube installed that was causing your same issue with the bolt not locking back. I measured the inside length of the tube, compared it with a name brand (mil-spec verified) buffer tube and found to my surprise, internal tube length was a little shorter. Once I replaced it, with a known mil spec buffer tube, the bolt locked back fine.

[Domingo]

Update took gun out this morning and it ran trows brass at 4 o'clock
I clean the bolt, the chamber and used grease on the BCG. Also lubed the recoil spring.
What ever I did it help
Thank you all

[Mr.1904]

AR15 short stroking?

Short stroking in an AR-15 is usually attributed to undergassing. And either out of spec gas port on your barrel, gas block, or an out of spec gas block hole (in the sense it does not line up with the gas port). But can also be caused by having the wrong buffer, buffer spring (check .308), or out of spec buffer tube.

I have also seen many more spec issues with homebuilt lowers that would leave most seasoned gun smiths and armorers perplexed. But with both main components being name brand i won't get into those.

If you were to buy that stuff from a store and were to take it back they'd immediately point to your reloads. But it could be a compound effort of a few different things to create the problem. I.e is the gun broken in? Was it properly lubricated? Do you have an in spec bcg?

Oh, and the magazines. Check and shoot all of your mags. If it runs with one, and not the other, it could be a mag issue or a mag depth issue (mag catch slot not drilled in the right place).

Food for thought.

[Mr.1904]

Update took gun out this morning and it ran trows brass at 4 o'clock
I clean the bolt, the chamber and used grease on the BCG. Also lubed the recoil spring.
What ever I did it help
Thank you all

Awesome. Good to hear. Sounds like it was just breaking itself in.

[supermario]

Anytime I have issues, I immediately swap out the bolt carrier group and see it if works from there. Then swap lowers. And just keep going with the process of elimination.

So far it has been the bolt carrier group each time.

[golfish]

check the gas port size. I had the same problem on my pistol, drilled it out 1/32 more and it runs like a champ. Might drill it out a bit more to see if it helps running Tula..