jackandjill 683 Posted October 4, 2015 So I have bunch of 9mm and 556 spent casings from last year. They have been in a open container in the garage for a year. Some have white/greenish bubbles and others (specially 9mm) look like complete rust (brown). When I scratch these white/green powdery bubbles, they expose copper like metal area. Are casings made of copper with brass coating ? I thought brass casings dont go bad. Is something wrong with the casings or the way they were stored open in garage ? Quote Share this post Link to post Share on other sites
T Bill 649 Posted October 4, 2015 Everything oxidizes when exposed to some level of moisture. Brass will show white and green like the Statue of Liberty. Toss them in the tumbler and clean them up GTG. Brown rust-like on brass is tarnish. Same rules as oxidation. Rarely will the brass be no good after exposure for a year in the garage. Brass is made of copper and zinc. Quote Share this post Link to post Share on other sites
jackandjill 683 Posted October 4, 2015 Cool. Will do. thx Quote Share this post Link to post Share on other sites
raz-0 1,256 Posted October 7, 2015 Brass is copper and zinc. If you have serious brown spots, and they remain after tumbling, it is likely a spot where the zinc was leeched out and the cartridge is no longer as strong. It is one of the reasons in not fond of wet tumbling with steel media and lemishine. It can hide such issues. Quote Share this post Link to post Share on other sites