There's really only one answer. You need a Picatinny stlye base, and there's only one person who makes them for Weatherby Rifles. Contact Richard Near at Near Precision http://www.scopebases.com
. My Mark V .300 Wby was all over the paper with Leupold bases, switched to the Near base and Badger rings (Richard wasn't making rings at that time) and now it's .5 MOA out to 400 Yds. (this isn't my longrange rig). The price is steep, but you can go this route 1st and cry once, or try all the other ring/base combinations and end up with this in the end. As has been said here before, there are hunting scope mounts and there tactical scope mounts. When you have a light rifle, heavy scope, and a lot of powder, you need to go tactical. If you decide to add a break later, you need tactical that much more.
Another note, don't let anyone tell you that a Picatinny mount for a Remington 700LA will work on your rifle, they are close, but a few thousandths off here and there, if you mount one, it won't be truely flat and you'll twist either the rail or the receiver.