For the sake of clarification, my intent with using jacketed ball to delead a gun was just to reduce the time at the bench getting it lead free. No doubt some lead remains in the rifling. The brass scrubber on a brush works quite well as mentioned. I have employed a Kroil soak in the past or still do if running jacketed isn't an option. If I'm really having a tough time I have a Lewis lead remover but I don't use the heavy artillery unless I need it. I go with an "escalation of force" kind of thought process!