I would make very sure that were I to follow a reloading manual, I would use exactly the same bullet and exactly the same powder they use in the manual's load development. The shape of the same weight bullets can be very different from make to make, requiring the ojive (curve to point) to make contact with the lands at different lengths.
With a Weatherby, part of the velocity achieved is due to freebore or lead. It is not there to be used in reloading, it is there for the rifle to use to "build up steam", if you will.
Ed
