What stops a charging Grizzly or Black Bear is multiple shots right to the head or to a shoulder that smashes on through. If you hit a shoulder and smash it you can sometimes turn the best away for follow-up shots but hitting a shoulder on a charging bruin is tough, so are head shots on moving critters. However, that being said, the largest Grizz on current record was taken, I believe, by an Alaskan Encon hunter who used a 7mm mag Browning semi-auto. He put all five into the bruins head at a pretty close range and then followed-up with a second mag full just to be sure. This bruin, by the way, had killed and partially eaten a hiler who plinked it with 5 38 rounds from a snubbie - they found all 5 38 rounds had failed to penetrate the heavy pelt.
The 06 can be loaded, or purchased at levels equalling or surpassing the 7mm mag but you need either a hot 180 gn or hot 190 gn load, at the minimum, to do that. 200 or 220 gn slugs might be better. One bullet I know of from a 300 Win mag shot through the shoulders of a medium sized Grizz at about50 yds - it was a solid brass slug from Barnes, I believe. However, all this being said I would hope thet J.J. Hack, who has tremendous experience hunting bear could chime in with some advice that could help. HTH. Mikey.