Ar-15 experts step in please..

[Hworth18]

I have an Ar-15 pistol in .556. I went to the range tonight and shot 40 rounds of PMC 55gr .223 ammo and the last round from each mag would not freely eject but would just lie on top of the mag after fired. What would cause this? I didn't experience any other issues other than I had to dump the spent brass from the last round after each mag.
Any help would be appreciated.
Thanks!!

 

[BrandonM]

What type of mags?

 

[Hworth18]

What type of mags?

Magpul PMags.

The last round seems to chamber just fine but after firing, just falls back on top of the mag?

 

[Capm_Spaulding]

Maybe need a lighter weight buffer tube or the extractor isn’t biting well.

 

[Gunbuffer]

Are you Shooting 556 in a 223 Barrel??
Hope not

 

[Hworth18]

Are you Shooting 556 in a 223 Barrel??
Hope not

No.. I have a .556 AR 15, I shot .223 thru it.

 

[Jwryan84]

Could be a lot of things. Prob needs to be shot more and oil the hell out if it, then see what happens.

I just put one together also, PSA is stupid cheap. It def feels gritty and tight, needs shot to loosen it up. This makes 11 AR's

 

[Annie]

The problem is it's an AR pistol. I had a similar problem with an AR of the not pistol variety, but it turned out to be a problem with the Pmag.

 

[Hworth18]

View attachment 123413 Could be a lot of things. Prob needs to be shot more and oil the hell out if it, then see what happens.

I just put one together also, PSA is stupid cheap. It def feels gritty and tight, needs shot to loosen it up. This makes 11 AR's

Thanks, I just thought it was unusual, my other AR doesn't do that.

 

[Hworth18]

The problem is it's an AR pistol. I had a similar problem with an AR of the not pistol variety, but it turned out to be a problem with the Pmag.

I'll try different mags and see if it still does it.