This 20x75mm shotgun shell is a specialty munition taking advantage of the greater payloads available to this class of shotgun. By using a softer tip of the explosive itself the nose of the projectile squashes against the target and releases more explosive potential towards it, while also being rather unpleasant for anyone standing nearby.
This weapon is not normally available to civilian sale without security clearances, and is available for 500ks for a box of twenty.