We went shotting today and my ar15 Jammed. Failur to extract fired round. Looked like it pulled the back of the rim off. What might have happened to cause this. I was using PMP new manufactured brass rounds. I only fired the gun 80 rounds today. but most fired with rapid fire.Could the rapid fire caused the barrel the get to hot and thous caused the case to stick in the chamber.

But there is a good ending to this. WE had a blast with the rest of our firearms. would you believe a 20ga would reach out to 150 yards with #4 3in. Suckured my buddy into shotting my Browning Gold 3 1/2in mag. It really doesnt kick any harder than a pump 3in with the 3 1/2in. The semi really takes the load off, but he was unprepared for the thounder of my turkey gun, hehe.
other gun we shot today


Glock 23
Sig Blue line 40 S&W
Makerov 9x18 (best little gun) forgot how fun  
           and accurate that little f*cker is)
Push Pull Smith Rubin 308
H&K clone Centrey Arms 308
Marlin semi 22
2 Ruger 10/22 with 30 round mags
Springfield loaded 1911 9mm
Kimber with 22 conversion
H&R Topper 20ga
Browning Gold semi 3 1/2in 12ga
Mak91 223
3 Bushmasters AR15
Varmiter wiht 24in barrel flat top
bushmaster with 20in barrel and brake
bushmaster with Wilson custom 16in barrel and    brake and bashmaster comp trigger. ( adjusted the first stage to 4# and 2nd stage 1/2#, really close to auto when bushy starts to rock on your finger with recoil and burn up ammo fast.)
 

I had the same thing with Spanish SS-109 ammo.  I changed the extractor spring to a Wolff heavy duty spring and have not had that type of failure again.  

I hope this helps.

Regards,
Gary

What brand of rifle?

Also who is the poor soul who has to clean all those guns.

I have big doubts about the ability for cheap ammo manufacturer's ability to control the quality of their product. PMP, Wolf and Norinco have substantial variations in powder load. For the AR this can be critical as a hot load makes too much port pressure and can cause the extractor to tear away or jump over the cartridge rim. (Shades of the M-16/ball powder problem during VietNam).

Cheap stuff is good for blastin', but for reliable function stick to the big name manufacturers (Winchester, IMI, etc) or military surplus. You wouldn't put 87 octane from Billy Bob's Gas-N-Go in a top fuel dragster would you?

I prefer AK jelly on my toast.


R/K