Well I don't, but TONS of people here have reported they do with minimal, if any, issues. There has been at least one extreme test of shooting steel case through an AR (via a blogger) and the conclusion was, yes, it does wear out barrels faster, but given the cost savings of that much ammo as compared to brass it more than pays for a replacement barrel.

http://www.luckygunner.com/labs/bras...el-cased-ammo/

OR