Oh I agree they did use steel cased ammo during the war, simply because that was all there was. Brass was very scarce then. But when the firearm was designed it was around brass casings.

With brass cases in the TSMG I've noticed notches in the bases where the extractor grabbed them. I know others with TSMG's that have fed a fair amount of Wolf without any problems. It could also be that my bolt is slightly out of spec.

Could also be partially due to the fact that the 80 year old parts aren't what they should be. Even today extractors are still surplus. When I add $10.00 and down time to the cost of a box of any brand of steel case ammo its not cost efficient.

Never had any issues in my modern .45's.
AR's and the like head space on the shoulder and not the rim. My mini 14 runs very well with all of the Russian imports, and I as well pick it up as I can.

I'm not saying that Russian ammo is all bad but watch your gun.
I know some who will only fire cast bullets to reduce barrel ware. When you have a 35 to 50 thousand dollar firearm you tend to pamper it a bit.