Just some of the reasons I don't shoot at ranges. I know the local indoor range here doesn't allow Tulammo, but I'm not sure if they "think'' that they mean all steel cased by saying that, as they sell range brass so might not want to have to sort it.
I've had more problems with Winchester White Box ammo than I have with Tulammo, in x39, .223 and 9mm. I reload the steel .223 as they have boxer primers. The bullets on the factory Tulammo are bimetallic which is a thin layer of copper plated over a steel jacket, but they have a lead core not steel. Just another case of people who really never bother to find out the facts. The steel jacket can however damage some type of backstops.