Want it pretty much straight from the horse..err.....griz's mouth?
Drop $4.99 on this:
http://www.amazon.com/Kodiak-Bear-Ma.../dp/B006Z1FHTC
The author, Keith Rogan posted here on TFL back in 1999/2000.
Keith survived a severe mauling.
Keith's first hand experience with being attacked convinced him a handgun, of any caliber, would be next to useless.