RE: 30-06 for brown bear
I wouldn' t go with anything bigger unless you are going to be bear hunting with any regularity. I would carry a backup handgun if I could...Something that has a caliber that begins with a 4 or larger... Or I guess bear spray isn' t a bad idea.
As long as you stay aware of your surroundings I' d say you would be as safe as one can be.
Too many bears have met thier end by a 30-06 for it to be that bad of a choice. It isn' t the best, but it' s better than alot of other guns.
Another thing to think about is the quality of the gun you will be taking. It isn' t a model 710 is it?
On the other hand, it may be fun to go out and buy another gun. But you may be better off using a gun that you know and are used to.