I have two barrels with brakes. I use both for prairie dog work. They both collect what seems to be a lot of carbon at the barrel crown. I know its due to the muzzle brakes, but has anyone found this effecting accuracy? My own personal O.C.D. that makes me want to scrub the crown every 4 or 5 shots. Is it necessary to maintain accuracy? If so, what cuts this tough crap the best? Thanks, Bill