I took my new custom build to the range twice now, and both times have left with shredded gas rings.
A little background first, the rifle is brand new, put together by me from parts I've gathered all over, the bolt and carrier were assembled by Global Tactical. If you click here it'll take you to the product description, and you'll see that the main components are made by CMT. The upper is Mega, the barrel is a carbine length gas system Del-Ton.
I did not headspace the rifle, as the barrel and the bolt were both new and supposedly in spec.
The first time I went to the range, I was shooting Monarch ammo, and after about 10 rounds, the bolt wouldn't seat all the way, and the firing pin wouldn't even touch the primer. The second time, after I replaced the gas rings, and cleaned everything out, I was shooting PMC ammo and got through about 25 rounds before I heard a *click*.
Here are some pictures:
1st time:
http://img.photobucket.com/albums/v6...t/_MG_4739.jpg
http://img.photobucket.com/albums/v6...t/_MG_4734.jpg
2nd:
http://img.photobucket.com/albums/v6...t/_MG_4744.jpg
http://img.photobucket.com/albums/v6...t/_MG_4745.jpg
As you can see, the damage is on the extractor side of the bolt and on the same ring both times. The pictures don't show this, but the damage is on nearly half of the gas ring, with the other side intact. Also, you can see a sliver of the gas ring starting to shear off.
Also, when I disassembled the BCG, the cam pin took a great deal of force to make that quarter turn, and there is an indentation on the cam pin where it meets the edge of the bolt:
http://img.photobucket.com/albums/v6...t/_MG_4748.jpg
I've checked the inside of the carrier, and it looks smooth. Also, the closest thing to a gunsmith at the range suggested it might have been headspace issues, but when he looked at some spent casings, he felt they looked okay. When I said that the rifle was put together by me from scratch, he said maybe I just eff'ed something up, but a cursory once-over of the rifle revealed nothing glaring.
So thats where I'm at, either there's something wrong with the bolt and/or carrier, or somehow I messed up the rifle during assembly due to my inexperience (this is my first build and first rifle).
One question I have (besides how to fix this) is why is it that only that one ring is getting damaged and not the others?
My next step is to find someone would be kind enough to lend me their carrier to pair w/ my bolt to try to troubleshoot the problem, but in the meantime, I would love to hear some theories on what could be going on. Thanks guys!

