I've looked on all the appropriate forums for information on issues of using steel cased ammo with the RFB, but I haven't found any hard evidence up to this point. I went as far as to call Kel-tec about the issue and was told that they were unaware of any reports of failures due to steel cased ammo, which makes me think it may be another unsubstantiated gun myth. I do however avoid steel cased ammo due to the coating used to keep the casings shiny, as it can gum up vital areas of your firearm and makes it harder to clean. The price for the Norinco ammo is pretty good, but you can get Federal .308 from Reliable Gun in Vancouver for the same price.