7mm REM also can form from . Best to find is .308 Norma Mag to form from as that is sister case .As I had a few 35s way back, the dark recesses are telling me that you can form 358 Norma out of either 338 WM or 300 WM in a pinch! It's not difficult if you simply cannot find brass. Good Luck!
None of the Norma mag brass is plentiful in America anymore7mm REM also can form from . Best to find is .308 Norma Mag to form from as that is sister case .