I have a cabelas tumbler, corn cob media, and cabelas case polish. My brass has soot around the mouth that will not come off in the tumbler. I do not resize first, and the soot just gets shiny with the brass. I can scour it off with a scotchbrite pad and the brass polishes up good. I tried running the cases longer, even over night without removing the offending soot.
Should I try a different media?
What do yall reckon?