Re: 300 WSM
channelcat,
I dont think Rem actually makes WSM actions or didn't. What needs to be done is to take a little off the edges at the entry point of the raceway at a time with a dremmel untill a case will pass with .015 clearance on both sides. You can then finnish the edge with emery cloth. I had to do it, it only took a couple light passes and wasnt hard to do at all.
If you really want a measurement, measure the web and rim area of a fired case and add .003 to .005
Good luck