Re: Can you make 300RSUM brass from 300WSM brass ???
I don't think so. I don't have the exact measurements on hand, but just eyeing up the two, the shoulder on the WSM is substantially farther out than the RSUM. The difference is a little more troublesome than just a few thousandths. I can't see how you would get around this problem, unless you cut, then went through a multi-step forming process. I would just use remi-spec brass, and be done with it.