Many are correct, let the barrel cool between shots at least IMHO. I owned a Vanguard 6.5-300 (since gave it to Grand Son) ran 900 rounds through it @ 3450 FPS average. Bore scoped it and thought there was a barrel issue sent to Weatherby for safety reasons. They notified me the barrel (nick) is from the rifling process and that the rifle verified shot .44 at 100 yards.