I've got a 325WSM but the 300WSM would probably be more versatile. I had to make a new reloading case holder as a result of the fat cases.
I got it several years ago before the case shortage and have a bag of unused virgin brass for it. I'm still using range pickup brass that I found in a bin there - was almost 2 full boxes worth, and it was in 300WSM (converts easily to 325WSM). I keep abandoned brass either for use myself or future bartering, the later being the case for the found brass (I found that brass years before I bought the 325WSM).
