The 30-30 is probably the most common round out there. They used to say the 30-30 has killed more deer than any rifle out there. Still? Who knows but their are a lot of them out there. 30-30 would take a bear out. I had two at one time, a marlin and the Winchester. Gave the Marlin to a neph who has killed many deer with it.

If I had to pick just one rifle...I think I'd go with the .308. Very accurate round. Relatively light recoil, Lots of it around. NATO round. Will take out any critter in North America. Has a wide variety of bullet types and weights.

The .308 is found in all manner of rifle formats from bolt to semi-auto's like the AR-10. Having shot one for some time, I think the effective range for the .308 is about 750 yards. They used to be, may still be, used in long range shooting by many peeps. Seems like the 6.5 Creedmoor is or has surpassed the .308 in popularity for long range shooting...but that doesn't diminish the .308's history as a good long ranger.

Old professor friend out in Texas has killed bunches of hogs over the years. He mostly leaves them in the field for the buzzards and coyotes as well. Really big problem out in Texas.