RE: 45/70's
Just, whatever you do, don't ask if its enough gun for bears[&:]!!! LOL, sorry the .308 for bears thread has worn me out. I'd say easily anything in North America, and yes shot placement would be key, and yes there are bigger badder mammer-jammers out there.
Do doubt someone will mention how "little" energy it has...but I think people get caught up in the numbers sometimes and forget that a 400gr bullet is gonna "keep" alot more energy than a 200gr bullet and so it doesn't need as much to began with.