The ammo i used was PMC X-tac in 5.56 and paid 869,00 dollors i think it is unacceptable for the firing pin to break over only shooting it less than 200 rounds. Plus to be told that i had the wrong bolt is total BS. i hope it all gets sorted out but i should have just bought a CZ cause the warrenty center is a 10 min drive away and i wouldnt have to wait 1 week or whatever time it takes to get a part.