Son In Law has a Leupold Mk4 6.5x20 on top his Weatherby 30-378 for past 6-8 years. AFAIK, no issues with scope/rifle holding zero.
I have the same scope on mine, works just fine, the reduction of recoil in the 165 grain bullet and the 180 is quite noticeable. If you have any issues with your rifle send me a PM, they are fantastic rifles in the right hand, and never ever fire your rifle with out ear protection while the muzzle brake is on the rifle, the muzzle blast is horrific !
