You don't have to be optimal with a shotgun blast, certainly you don't have to be perfect.
IMO, one has to be as perfect with a shotgun as with a a rifle because, at typical HD distance, a shotgun pattern is essentially about a 2" hole.
I wasn't talking about shot placement, I was talking about ballistics - I meant you don't have to have the best of the best of the best ammo in your shotgun for it to be effective.
For the 9mm there is everything from snake shot, Glaser Safety Slugs, EFMJ, FMJ to 147gr. JHP
Some of those loads can potentially get you killed because they are not effective. I think with handguns in general and probably more so for chamberings like 380 Auto, 38 spl, and 9mm - you need to have a good performing round, near optimal.
What I'm saying about the shotgun is that it is so devastating that the differences in effectiveness between #0, #1, and 00 Buck probably do not result in any real difference in the outcome of a confrontation because dead is dead - or incapacitated is incapacitated. Yes #1 Buck results in 30 percent more wound trauma, but at some point it might not make that much of a difference.
It's like saying falling 10,000 feet onto concrete is more lethal than falling 9,000 feet.
Double aught buck works, it's proven to work. So I can understand people sticking with that loading.
(even though #1 Buck is better
)