A Black Bear is a black bear...30-06 will be more than adequate to deal with the largest black. If you're hunting with a guide in bear country I'll bet he's packing some serious bear medicine in case you encounter a brown. If I was on my own in Alaska bear country I'd probably want something beefier for security.
I still have my doubts of the ability of any hunting round to bring down a charging brown after he's decided you're dinner. Personally for that scenario I'd want a 12ga loaded with a mix of slugs and the heaviest gauge buck I could find.
For most on here there is a dream trip floating up around in their heads but there is a question of how to pay for it. This has been a problem for all hunters that wish for that elusive moose, bear, goat, sheep, elk, deer, or any other hunt where you are required to hire a guide or you choose to hire one for that hunt of a lifetime.
First off I am not a financial planner I am just a hunter that learned a long time ago that even with a great job there are going to be some...