I shoot Wolf steel cased 30 Carbine ammo and while I have heard that the steel is hard on the extractor I have not had any problems in over 1000 rounds. I would prefer to shoot brass cases but unfortunately I do not re-load that caliber and don't want to pay what they are selling for.

I purchased a few spare GI M1 carbine extractors (5 bucks ea.) so if I do chip one I'll just change it out - no biggie.