I had a friend who used the shoot the diamond dust down the barrel method... he ruined the barrel in about 5 shots.. it was clean and smooth alright..it looked like a shotgun for about the first 6 inches... if your going to actually do it and if it's a factory barrel I wouldn't waste my time, then do it sparingly as in very sparingly...I would only use the JB paste method and only a little bit..maybe just shooting it will smooth out a problem area over time....just be careful especially if you just spent $500+ for a custom chamber and barrel...