my liitle beloved brother brought his shotgun to me complaining that its kicking harder than normal (DALY 12GA semi auto ) well ,I asked him it he cleaned the bore ? oh I am supposed to to do that ? checked it and looks like someone peened the inside of the barrel , because of plastic build up , any good way to remove all of this plastic , I have scrubbed with a brush , solvent for plastic , ect , all, except honing the bore ,ive spent 2 hours cleaning this sucker and still have fouling , any good Ideas to scrape this crap out??