The .410 load is nothing to sneeze at, and I'd use it if I really disliked 12-gauge recoil. But people more knowledgeable than I say that the only sure way to stop a conflict immediately is with a hit to the CNS. #1 buck reliably penetrates deep enough to hit vitals, and 15 of them can be packed into a standard 12-gauge shell. This basically triples my chances of hitting the CNS with a COM hit as compared to the 5-pellet .410 load.
That's not to say the .410 is a bad choice, but for a lot of people, it's not a better choice.
As for the 9mm to 10mm analogy, I understand that there can be such a thing as too much gun for some people. And if a .410 is what a person can comfortably handle, that's fine. But I believe the other factor in that equation is cost of ammo/practice. I suspect if 10mm ammo were as cheap as 9mm ammo, a lot more people would be using the bigger gun.
Among shotguns, the bigger 12 or 20-gauges are already cheaper to shoot than the .410.
Last edited by idek; November 9, 2012 at 05:08 PM.