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.
There can be too much of a good thing with antler rattling.
I like to hit the horns together for a good 30- to 40-second rattling sequence and then hang them up and resist the urge to hit them again.
This works to the hunter's advantage, because if a buck has heard it, he may have been 300 or 400 yards away and he comes in and he's not exactly sure where it came from.
When finally is time to rattle again throw a slight change-up into the routine.
The second time, don't rattle as loud...