I took my AR10T carbine out the last couple of days, and ran into a problem. Yesterday, I had a Failure to extract for the first time, then the rifle didn't go into battery. I got the cartridge out, which was a reload, and thought it may have been an improperly sized case. So today I took it out with some NATO Standard M80 ammo. The first four rounds were fine, then I had another failure to extract with factory ammo. I got the empty case out and went hunting for the other empty brass. Of the five cases, the one that failed to extract and one other had part of the rim with metal torn away, like the extractor had grabbed hold then came off the rim, taking some brass with it. My LGS guy is thinking the chamber is a little smaller than spec, causing the cases to stick, although I was able to push them out with a cleaning rod, and even though this has never happened before in the three years I have owned and shot the rifle. Before messing with that, we figured replacing the extractor would be worth a try. When I broke the BCG down, I found the rubber washer on the extractor spring was broken, and there was a substance like red loctite in the center of the spring that was preventing it from compressing. Do you guys think that may be the problem? I won't get a chance to go out shooting for a few days, so I won't know for sure for a while. If it still does it, we are going to carefully polish the chamber. Being a "T" it should be a snug chamber, just don't know if that is the issue or not.