Big caliber semi autos?

[BBDartCA]

I would go with the 12 gauge with slugs. You are probably shooting close-in and slugs <25 yards are devastating.

 

[Gunner3456]

I would go with the 12 gauge with slugs. You are probably shooting close-in and slugs <25 yards are devastating.

With a fully rifled barrel, it's about an 8 inch pattern at 100 yards with standard slugs. With sabot slugs, 2-3 inches. With standard lead slugs you don't get the speed, accuracy or JHP expansion but you're right, they are still devastating even in a smooth bore.

 

[coosbaycreep]

Or instead of a 12ga, you could get a ruger .44mag carbine. They're a reliable semi-auto, hold 5 rounds, and they're lighter, quicker handling, kick less, and are easier to shoot than any shotgun or .308/45-70/etc.

 

[bmw2]

Ballistically, a 7.62x39 is very similar to the 30/30. Lots of blackies have been taken with that, just pick up a box of heavier soft points.