RE: Butch's Bore Shine?
Any time you suspect that a solvent might hurt the finish on the barrel, pick a spot on the barrel that can not be seen and test the solvent there. I like to remove the barrel and do it on the underside where the stock covers anything. I have found very few solvents that seem to hurt a good quality blueing on a barrel.
When I purchase a solvent I look for one that is made for black powder rifles. Although I do use bore scrubber which can be used on anything, and is a great solvent.
Some some solvents can cause flash rust. One solvent, MAP a homemade solvent (murphy's oil soap, alcohol, and hydrogen peroxide) will cause flash rust.