For dangerous game, I think most(all) use a heavy back-up rifle regardless of what rifle the hunter is using. He has no idea, if in a bind, how the hunter will react. I sure as heck would!! And I am sure the hunter would be glad someone has his back(no pun) intended.

I have a SS Ruger #1S 45-70 I deer hunt with. Never really thought of it as a carbine though. Have had several #3 45-70s also over the years. The #3 will take the same loads but will hurt a lot more. My favorite deer load is a 300gr JHP at 1600 fps. I know it's pretty mild but will go clean through both sides on a Michigan deer. Ruger also made some #1H Tropical weight 45-70s some time ago. Now I could really go for one of those but the 26" looks equally cool. Can't get them all but have made a serious dent in trying.