Sounds like tolerance stacking to me. Maybe Weatherby could shed some light on this, but the easy fix is .022" of shim under the base, or a set of Burris Signature rings on your existing bases and use the offset inserts to get back your .022" (you could use a .020" offset in one ring and a zero in the other, or two .010's, or if you'd like more elevation in your scope, you could use a .020" in the front, and a .010" in the rear (set opposite each other, obviously) and get .030" of elevation back into your scope, giving you a tad more reach if you shoot long distances. I love my Signature Rings (I have them on a Mark V that has the same problem you describe, but about .026" of droop in the rear).