A friend of mine that was getting out of the reloading hobby sent me 1400 .45ACP cases. They are extremely tarnished, some to the point of being black. I have had them in the tumbler for over 8 hours in corn media, two hours before that in walnut, and they still are not polishing up like I want them to look. Although I've never done this before, I added some Brasso to the media, (about a tablespoon). I'm waiting to see how they do. Does anyone have any ideas? Thanks in advance.