There have been a number of .22 Hornets, .22 LR and such in Double Rifles. A .410 would be the way to go in a shotgun action.

I am not a Hog expert but I would think that a slug wold be better. I think that a dedicated shotgun for slugs would be the best option. That , of course, assumes you don't want to spend the bucks for a true Paradox.