#1 actually has the greatest cross sectional area per weight of any shot, but it's not very common. 00 buck is real common, and stacks nicely in a 12ga shell. It's like 9 or 15 .380s per shot. I have an SX3 with 11+1 of 2-3/4s. That's like 108 .380s, nine per trigger pull, and it can fire as fast as an M2. Talk about a wall of lead; there's nothing else you can carry in your hands that will put it out like that. No SMG can compare.