ipsc - check your mailbox.

Indy - The .270 is adequate for black bear, provided you use the proper bullet and do your part putting it where you need it to go, just like anything else. It's a proven elk and caribou round, as well.

Not sure I'd be completely comfortable carrying it for grizzlies, especially the coastals. I know a couple of guys who've downed interior grizzlies with .270s, but seems just a bit too adventurous to me. I'd look at the .30-06 as a minimum caliber for grizzlies, but won't go so far as to say that it can't be done with a .270.