If you were hunting hogs while walking, planning to jump them up from bedded down, and shoot them on the run, not knowing what size you might jump (small to large, but mostly medium-sized), and you had to use a shotgun, would you use a slug or 000? My buddy says buckshot is fine; I say a slug would be necessary for penetration. 12 ga 3" mag shells have 10 triple ought pellets in each shell, .36" each.
http://en.wikipedia.org/wiki/Birdshot#Buckshot