The other scopes were a Zeiss 6x20x50 and Swarovski z5.
Well there are many things to check. Like action screw torque, mounts or rings loose, recoil flinch etc. But one thing I have had on some of my Weatherby's is Leupold failure. Two of the higher end Leupolds in one season, both on Weatherby's. I would run through the check list then swap scopes just to see.
Just curious if you used a chrono on the weatherby? I used a accumark .257wby with 2 boxes of factory 110 accubonds. We got 3moa at 100 yards and as much as 175fps differance between shots on the same box of ammo. This left us scratching our heads. At $70+ a box I would have thought it would be better.
My 257 shot a 3/4 inch group at 200 yards with factory 110 Accubond ammo. Perhaps you got a bad one?
As others have said, check all screws and switch the scope. I do not like shooting over lead sleds. To many variables. If I can't get a rifle to shoot the old fashioned way, with a bipod and rear bag or over a cement bench, because of recoil, you shouldn't be shooting it anyway.