The material that I mentioned is Methyl Isobutyl Ketone, which dissolves the major component in smokeless powder. When it comes to the hard stuff, I doubt that there is much nitrocellulose left to dissolve, but It really gets the other stuff out very aggressively, for about $8 for a 12oz. spray can. I friend who has tried about every rifle cleaning solvent told me that it works as well or better than the best of them. As far as using ammonia in barrels, you might want to ask Jim Borden about that. I will also relate a story. A very long time ago, Merrill Martin wrote articles for Precision Shooting. He could afford to do a lot of experiments and he did many that were interesting to me. One time I was talking with him by phone and he mentioned that he could identify barrels that had been cleaned using Sweets by inspecting him with his bore scope. Knowing that he was going to that year's Prairie Dog Conference, that was put on by a friend, and knowing that Merrill could easily afford it, I suggested that he show up with his bore scope, a video attachment, and a monitor, and prove his claim to any of the participants that cared to have their barrels inspected. As I understand it, he was able to make good on his claim. Certainly there are solvent based bore cleaners that contain ammonia that are safe, but not all are. Yes, I remember Blue Goop. I even made and used some back in the day. Luckily I did not leave it in a barrel for long, and I rinsed it out, and then dried the metal quickly, but just like me, in those days, and even today, most shooters do not have a bore scope, so they are often guessing and assuming. One of the great developments that have come along is the advent of affordable bore scopes with digital cameras built in. I have convinced a couple of shooters that I am helping to buy them, and they have been great tools. They email me pictures, and I tell them what they are looking at, and make suggestions as to proceed. Hard carbon is a real bitch when it get so bad that you cannot see any steel for a ways past the throat. I believe that the leading culprit is using brushes for way too long, but even without that, solvent alone cannot keep the problem from happening, with one exception that I know of. Shooting VV133 in a PPC and cleaning every 30 rounds or so, I never had a carbon problem using Butch's, patches and bronze brushes, brushing about one cycle per shot. During that time, I had the use of a bore scope.
