I'll admit that until the armor-piercing flechette ammo came out in WAR!, I never once considered putting shot in a shotgun. I always use ExEx, APDS, SnS, or Shock Lock rounds. I have had characters that carried two shotguns, one with lethal or SnS ammo, and the other one sawed off and on a sling, with shock lock rounds, as a 'master key'.