When I clean, I will run 3-5 patches soaked with Barnes CR-10 through until the powder fouling comes out. I then scrub with a bronze brush several strokes, adding drops of CR-10 every four or five strokes. I then run a few patches through again soaked with CR-10 to get all the blue out. I will repeat this process two or three times. My question is this: At the end of my cleaning session, my bronze brush will start to "scream" for lack of a better term. Does this mean I have cleaned it down to metal?? I get no more blue on the patches. And it does not "scream" the first couple of times I do the cleaning session.