I have a 23 year old muzzleloader that has been hunted hard with every year I ahve had it. The only reason I used JB bore paste was that I had some barrel imperfections creep up over the years and the JB bore paste took them right out. It helped my ol gun load easier and my accuracy improved. When I first got the gun I thought I was cleaning it out good enough but must of been leaving a tiny amount in the first 6 inches of the barrel. Over the years it became harder to clean and the bore paste eliminated the rough spots in that area.