On several occasions today (after shooting roughly 100 rds through the gun), the trigger failed to reset. Bolt was completely closed, round properly seated in chamber. After manually ejecting round and re-charging the rifle, it functioned normally for a couple rounds, then same malfuntion occured again. I set it aside for a time, as I was zeroing several other firearms. After a half hour or so cool down period, I loaded 10 rounds in the mag and it performed flawlessly. I initially guessed debris in the FCG, but allowing the rifle to cool down, would have no effect on this problem AFAIK. This rifle has been well maintained with only about 500 rounds through it. Getting ready to clean it tonight. Any suggestions?