How can you vote against the .30-06?
Hey I was going to say that!
For hunting in N. America that will take just about any critter. But for SD I've been thinking about going bigger than my 30.06. I've been flirting with the idea of getting a .45-70 but I'd rather have the Marlin guide gun because the Ruger #1 only fires the one round. You may find there's more than one bear wishing to chew on you. Not likely but possible. Bear attacks are getting a lot more frequent BTW. There have been as many in the past decade as there have been in the century before that. And the 90's was the decade of the highest number of attacks before the 2000's. There's a lot more bears and people are out in their backyard a lot more. ATV riders have put people in contact with a lot more bears. But I've seen quite a few in the past 5 years while I only saw one in my 50 years before the last 5 years. Bear populations are exploding around my area like deer did back in the 80's. And I've had a bunch of run in's with them too.
Still if you're hunting you don't need to shoot until you get that perfect shot. Nailing a charging bear is another thing altogether and I'd just as soon have more power in case it ever actually happens.