Geissele URGI near clone 14.5 short stroking when suppressed with SOCOM Gen 2

[andy t]

Rifle: Early Geissele URGI near clone with 14.5 DD barrel. The rifle was using carbine buffer. I was using IMI 77 gr razor core ammo. Surefire SOCOM Gen 2 suppressor.

Without suppressor - normal function.

With suppressor: brass ejected at ~ 2 o'clock, failure to lock on empty magazine (happened twice). This seems strange as a suppressor should help with gas pressure. What could be causing this issue? I experienced no issues with this rifle and different ammo.
I also realized that I was using OK 20 round magazine. I didn't have a chance to try it with 30 rounders. Could this magazine also have an effect ?

[jackblack73]

Something similar happened to someone about a week ago. I don’t think you’re short stroking. I think the BCG is out running the bolt catch. Carbine buffer is too light. Try an H2.

[1168]

This.

But also try a different mag before you alter the gun, just for S&G. The rifle this clone is based on does not use a H0 buffer.

[Pappabear]

I had this happen and yes your bolt is outrunning. A different mag, ie 3rd gen Pmag have much stronger springs and work best. OK and Colt 20 rounders have weakest springs even though I run them a lot.

I also changed to an A5 buffer and it fixed it with Colt 20 rounders although new Pmags worked just fine. I was running a KAC 16 inch SR15, so not a shitty gun. Not the best mags are the real issue is my guess.
PB

[markm]

Ditch that shit carbine buffer and get an H2. The bolt speed is outrunning the bolt catch.

The standard carbine buffer is NOT appropriate for any decent AR-15 EVER!!!

[prdubi]

Mines did the same until I got the H2.



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