have you read about the collet resizing die by larry willis? I think I have to use one for my 300wm. All my brass is bulging above the belt in the "web" I guess they call it. This collet die brings the size back to around .510, instead of my .514 measurement, then my redding die should work I hope, that die is .507 inside diameter. Larry said it is worth the money because it is less abuse on the brass and die. Also I'm getting Imperial wax from what I read it is the best.
Hope this helps , His website is Innovative Technologies - Reloading Equipment