I am not John but do know a little about bear hunting, scopes and the 375 Ruger.
My 1st choice is the little 2 1/2 X Leupold compact. It is tough and lightweight and if you need to magnify a bear more than 2 1/2 times you need to stalk closer.

My 2nd choice is a tossup between the 1-4 or 1.5x5 Leupold Vari-X

Phil Shoemaker
Alaska Master Guide,
Alaska Hunter Ed Instructor
FAA Master pilot
www.grizzlyskinsofalaska.com

Anyone who claims the 30-06 is not effective has either not used one, or else is unwittingly commenting on their marksmanship.