"At close range, as inside a bodega, accuracy isn't all that important. Big BOOM in a small space can be a huge psychological deterrent to anyone in front of it............"
Thing is, though, well-placed shots would cut down on the damage to your stock. Thinking about it, I think I'd go with #4 shot in that kind of situation. Center of mass shots probably wouldn't blow out the backside. Save more merchandise.
But you're right. A couple of examples, and the rest would probably be gone. Maybe the 6-round capacity would be enough.