A revolver w/4" bbl would be adequate but not ideal.

The first feral pig I ever shot took two hits from a 308 to stay down permanently. Kind of made me skittish and the next time I wondered if I needed a bigger rifle . Fortunately, about two years later a friend convinced me to try feral pig with a Marlin in 357 magnum. I had a blast and went out afterwards and bought an 1894C. I hunted pigs with that Marlin until California went soft on the condor. After I figure out a good load for the 140 gr Barnes, I'll probably use it again.