I guess everyone is an expert & if someone wants to look at a grizzly coming fast to "eat your lunch" with a marginal caliber in your hands, be my guest. I killed a mountain grizzly that was coming at me & my guide at a dead run in 2001. The shot was head on at 35 yards. I used a .338 RUM that stoped the bear. I would have only been able to fire once. The .30-06 is a great allround gun. If you feel you can stop a big bear at that distance go for it. Remember, the real issue is stopping a bear not killing a bear. A .22 will kill a grizzly.