This happened yesterday; we were shooting some targets and I brought the AR out. It had been sitting in the shade for about ten minutes so the barrel was about 80 degrees. I've been shooting steel cased for over a year with no issues, although I had heard about problems. Anyway, I chambered the first round, pulled the trigger, and there was just a click. Assuming it was a misfire, I tried ejecting the round. The bolt moved a centimeter, no more. I dropped the magazine and took it over to the sidewalk. I tried the butt-on-the-ground trick to eject the round. The bolt moved a half a centimeter and that's where it has stayed. I popped the buffer tube off and looked in there after an hour, I noticed the firing pin looked off. Has anyone ever had this happen with a cold rifle and an unfired cartridge? Should I just take it to a gunsmith?