I'm refinishing a CVA double barrel 12 gauge and I had to clean up the muzzles with a file.There were still a lot of machining marks on them. It left the crowns with very sharp edges. Does a thin shotgun barrel need a crown at the muzzle or should I just radius the edges over? Unrelated, but I was surprised to find that the case hardening on the tang is real and not chemically applied. Thanks for any tips.