Well where do I start.The magazine is hard to lock in place. It takes a real hard slam on the bottom to make it lock, just doesn't feel right.

I chambered the first round and squeezed the trigger, it fired but the bolt does not cycle. I manually chambered another round and pulled the trigger, nothing. I examined the round and there is a very small dimple on the primer but not enough to fire the round.

I tried using the forward assist, it didn't help. It is a DPMS lower with a GSE buffer tube. The recoil srpring is very stiff.

Any ideas? Thanks

Wgs

First what kind of upper-factory built or home built?

What kind of mag usgi?
Ammo?
need more info to help?


Where are you in Az

Also post this in the azhometown forum

Neanderthal

Quoted: Wgs First what kind of upper-factory built or home built? What kind of mag usgi? Ammo? need more info to help? Where are you in Az Also post this in the azhometown forum Neanderthal

The barrel was purchased on line from Gun Broker. I'll have to get more info on it.It has a gas block in place of the front sight. All of my mags are surplus and and function perfectly in my AR rifle. The ammo is store bought 55 gr. I was thinking that maybe I should use some MIL SURP ammo....62 gr. Something a little hotter perhaps.

ammo should be ok
mags ok

Need more info

bolt & carrier  mfg?

Did you headspace your upper ?

Send me your contact info thru IM

Neanderthal

Better start at the beginning and make sure there is a gas port in the barrel.

If it's the pistol barrel I was looking into (on Gunbroker), then I believe it's a Shaw.  Model 1 sells the same barels.  

Is the gas port "super tuned"?  (From gunbroker description)

Is the mag hard to load with the bolt forward and 30 rounds in a 30 round mag?  Or is it with the bolt open?

The small dimple may be just from the floating firing pin.  Does the bolt cycle at all, or does it short stroke?

+1 on the HS check and gas port check.  Make sure the gas port in block matches barel port.

You could try your pistol lower with your rifle upper.  This will function test the lower.  Just don't try the other way around!

I know it's March and you're in AZ, but what was the temp?  

Quoted: If it's the pistol barrel I was looking into (on Gunbroker), then I believe it's a Shaw.  Model 1 sells the same barels.   Is the gas port "super tuned"?  (From gunbroker description) Is the mag hard to load with the bolt forward and 30 rounds in a 30 round mag?  Or is it with the bolt open? The small dimple may be just from the floating firing pin.  Does the bolt cycle at all, or does it short stroke? +1 on the HS check and gas port check.  Make sure the gas port in block matches barel port. You could try your pistol lower with your rifle upper.  This will function test the lower.  Just don't try the other way around! I know it's March and you're in AZ, but what was the temp?

Yes the mag is hard to lock with the bolt closed. I can chamber a round and it will fire when the trigger is pulled, the bolt does not cycle. There is no extraction. I can manually chamber another round and pull the trigger, the round will not fire.

The day I took it out it was around 65 degrees.