Thread: Why…? Rings marks/scoring brass after FL resizing?

Originally Posted by Micky Duck

... give the bulgy bit/expander ball a polish using the drill and fine wet n dry then steel wool while you are at it..

I'm not sure what relevance this has to the outside-of-case marks. Also, from what I've seen of the smoothness of most expander balls, this may roughen up the inside of the neck, not improve it. At the very least, you'll be then guessing as to how much the case neck diameter has been changed from this arbitrary modification.