RE: grizzly caliber
Most of the Grizzly bears on this planet were killed long before the 338 and 300 Magnums were even in use. Calibers like the 30-06, 270, 30-40 Krag,300 Savage 44-40,45-70, 45-90 and yes the 30-30 and 303 Brit, not to mention muzzle loaders and shotguns.
NOTE.. I recommended the 375 H&H and 416 Rem Mag.