During a match today, I would camber a round and squeeze the trigger but nothing would happen. When chambering another round and looking down at the rear of the bolt I could see that the "firing pin assembly" (that little button in the rear of the bolt) was already forward as if it had not been cocked. This happened several times. Sometimes it worked, more often it would not. Tried different magazine without any luck. I shoot FGMM and this has never happened before. About 150 rounds through the rifle total. I could not recreate this while dry firing with snap-caps. Anyone seen this before?