My plinking rounds for the 500 S&W are either 275 gr Barnes XTP (factory) or 325 gr Speer GoldDot (hand loads). Both are accurate and pleasant to shoot. There is a 500SPL lightweight "special" load for the recoil averse. It's makes for a more tolerable experience with the shorter barrel (lighter weight) versions of the 500 S&W revolvers.
Agreed...I wouldn't buy that survival kit, I just posted it so that people could see that gun manufacturers are taking the bear threat seriously. I suppose it would be good for pilots or to keep in your car trunk or under the seat as a secondary weapon in case you have an accident or a breakdown in bear country. I suppose in such a circumstance you could remove your carry weapon and take the .500 along instead.
I regret that I haven't yet taken the plunge for a .500 myself....my biggest is merely a tiny, little S&W 629 .44 mag with the 8 3/8 barrel and an optical sight which is FUN to go plinking with...I live in the city and don't get out to bear country nearly as often as I would like.