Actually a 30-06 is a good bear rifle if you load a good bear bullet. In Alaska when I was a kid, the 30-06 was the #1 most popular grizzly caliber sold up there and used by more of the locals than any other with the 375H&H being in a close 2nd place. But nearly everyone used 220 grain Round Nose bullets on Grizzlies from their 30-06s.

If you can shoot well, the 30-06 is good.

I like my "big guns" and I carry "heavier-hitters" around the grizzlies as a rule, but I feel OK with my 30-06 and my 8X57 when loaded with the correct ammo.