I may be one of those guys who wears out a barrel by over-cleaning but when is enough enough? I can get clean patches even following a nylon brush but after running a bronze brush, things again turn black again, even after about 5 cycles of brush followed by a patch. And this is following only 10 rounds through the rifle. Do bronze brushes create a false positive? Is the brush slowly eroding to small particles that look black (brush has lost 0.010" in diameter after 91 strokes through the bore)? I know colloidal silver (small silver particles) are black even though the bulk metal is shiny. What are others experience with this? Do I need to keep scrubbing with the bronze brush until a following patch comes out clean? Thanks for any input.