RE: OAL Issue
Well, in general, most magnums have some freebore. My 300RUM's max COL to fit my mag was 3.65" but I would need to load to 3.82" in one, 3.75" in another to reach the lands. My STW same thing. Win mags I have had usually don't have that muchfreebore but yours sounds like it does. Weatherby's have over 1/2" sometimes. Its the way they are designed. So you have only one choice if you want to use it effectively for hunting. Load to fit your mag. Shoot it and see how it does. Its a luxury to be close to the lands, but surely not a must.
So there was a guy in another forum that had a 300RUM built same time I did. He said he was having a custom throat where he could reach the lands in 3.6". Well, it didn't turn out so perfect. It was accurate, but he had to throw away any commercial reload data. He had trouble reaching the starting load without pressure signs in some cases.
Oops, meant freebore.