The steel case expands just fine. The initial horror stories about the Ruskie steel cased ammo was the lacquer on the cases gumming up the chamber area causing mis feeds and poor extraction in the semi autos.
Steve,
If you want to try some of the Wolf steel cased 223 in your new rifle I've got a partial case of it and you're welcome to some of it. It dosen't shoot worth a crap outa my AR.
Drop me a PM with your number, I'd like to talk with you about yote hunting.
CR