I have a 22-250AI that I've tried to push the heavy bullets with highest velocity. It was made by Rock Creek BBLs its SS and 8" 5R Cut rifled. I've had under 400 rounds thru it. Could it be burned up? Been shooting some swamp works (JLK) LD bullets 65gr at 3,600 + Some of the bullets fragmented in flight other grouped into 3/4 MOA and less.Powder was H4350 and Re#19.