Yesterday at the chrono my A-5 kept shooting hot, If i keep pulling the trigger, say maybe a shot per second, i could adjust the velocity down. But when you stop pulling the trigger, it would shoot back up to about 300 maybe a little over. Any ideas what might cause this ? The only upgrade's are polished internals, Tech T ZKH, and H.E. grip. I have other mods but none which would affect velocity. I'm thinking maybe a problem with the power tube ? Any help or ideas would be greatly appreciated. Thank's.