Barrel cleaning discussions need to be divided into two categories, factory, and lapped. They are that different. Getting to the question, if you examine a new brush, it is larger in diameter, and the bristles are longer than one that has been used, and somewhat irregular in how far they extend from the center of the brush. After it has been used, even if no copper solvent is involved, the bristles are of more uniform length, and have ends that are squared off. This is from being abraded against the interior of the barrel. As this process takes place, particles of bronze bristle material are distributed throughout the bore, that will react with the ammonia in a bore cleaner like Butch's if the bore is left to soak after brushing, pretty much guaranteeing a blue patch. For that reason, you should not assume that the color is an indication of what a bullet has left behind on the surface of the bore. To get that sort of a reading, a couple of wet patches need to be run through after brushing,to get rid of most of the bristle residue, before letting the barrel soak. As far as copper solvents and brush wear are concerned, with something less extreme, which is all that my barrels require, simply pulling the brush through a rag or wadded up paper towel that I have drawn the rod through, seems to get the job done. The brush is dried sufficiently so that my brushes seem to last well. Others may clean with brake cleaner, which I do not like, because what one sprays, without protection, one breaths. Others have found that rinsing with alcohol does a good job.
