Why not go with a shotgun? I mean you can have those different loads, anything from birdshot to buckshot and slugs? I mean, You can go pretty light on the shot for smaller animals, slugs can take deer if need be, and I would feel comfortable against a mountain lion with slugs (comfortable is probably the wrong word) There are also combo rifle/shotguns, able to take some birds, but still have a caliber like .30-30. Just my $.02.