Short range large knock down power with penetrating shrapnel.
Would be a good choice for a 250 pound home intruder wearing body armor. Unfortunitly it real target is most likely close combat urban warefare or for BLM members.
Even with standard\rifled slugs you are pretty much lobbing them out there anyway with a .12 Gauge. With a slug this heavy your aim would probably look like shooting a mortar at anything past 30 yards. /