for the 30-378 the burris black diamond 4-16x50 posi-lock
w ballistic mil-dot retical. is the most resonable that is what i have used for a few years on mine and it is awesome.
I just upgraded to the Schmidt bender 4-16x50.
Jim and John lazzeroni recomend only those 2 scopes for there magnum rifles as they hold up very well to the heavy recoil.