Just got back from a P dog trip. Before we left me and my father-in-law reloaded 1300 rounds of 22-250 for my remington and his savage. Mine shot great the entire time, every one fire and went where i was aiming. His factory heavy barreled model 12fv savage however would shoot 3-4 good then the next would land 40 yards short or 40 yards to the right or.... then then next 3-4 would be on target again. What would explain this. Scope is fine, mounts appear to be fine. The gun has maybe 8-900 rounds down the pipe, could it be shot out?