Ok. So a firearm in pig country would be coined a gun, "of sudden pig oportunity"; be it agressive in nature, or not. I would opt for a repeating , handy long gun. Long guns have a tendency to bring a final outcome more reliably than handguns. Lever guns are a geat choice, and offer a wide array of calibers. The 30/30 is a great choice, as is the 45/70. 45 Colt and 44magnum, with correct loads are good choices. Obviously shot placement is paramount. My 2 cents.