RE: gun's for big hog's 400lbs+
I personally prefer a Marlin 1895 Guide Gun .45-70 with a good all lead hardcast.
A buddy of mine years ago used to use 12ga shotguns, for most hunts he'd use a goose-gun, long bbl with slugs, on other hunts he'd end up using a "Riot gun", tactical shotgun basically, with slugs and buckshot mixed.