Looking at the drawings, it looks like the shoulder difference is only about .120" or so. Of course, you also have to cut the Weatherby "double S" neck/shoulder but I don't think that would make a huge difference.
If my small lathe had a large enough bore, I would be tempted to try it a little at a time if I had access to a reamer. Worst that could happen is you take too much and you have to take it to a gunsmith to take it back a thread and recut the chamber.
Still shopping for larger lathe.....
Bob
