Every kind of training for self defense i've ever had, seen or heard about says aim for the center of mass - body. Biggest and eaisiest to hit.
go shoot some IDPA and you'll find real fast htat heads are small. You need to take time to aim and the target best be standing very still to be sure to hit it.
first, ANY time you need to pull a gun to protext yourself will be a bit of surprise, right? Unexpected. Heart races. Mind races..decisions decisions..get it wrong and you can die..or go to jail and face large legal bills, and even if you get off it can suck.
So..how well do you handle stress? make life and death decisions under stress? Some people do fine - others not very well at all. Most of us never have a chance to be tested.
House catch on fire and you do what?
Someone has a medical emergency, how did you react?
Car accident and you did what?
Made the right decision, instantly, every time? No second guessing, no better choice could have been made?
Much easier to hide/conceal/present a hand gun, especially in a tight space, over a 25-30" shotgun.
yes, birdshot looks impressive - go shoot something SOLID with it - penetration counts for a lot - you stop someone with a hit to the central nervous system (unlikely) or make them bleed out. You gotta hit vital organs to do that.
I know some people that love the idea of Liberty Ammo - very very lightweight and fast wtih a huge hollow point. I've seen a 9mm go through a police vest in test, explode a ham in a test - but 70gr 2000fps has little mass. A 230gr 45ACP at 800 fps stops better. A 357mag stops better yet.
Reality is few people want to be shot, or shot twice - so they'll stop. BUT if you need to keep shooting to stop them...based on my attempt to kill a few critters in the yard (ground hogs, raccoons) with a 22LR I want about 100 round magazine! 10 just doesn't make you feel good when they're still coming at you and the gun goes click!
Thankfully it's small rodents and not a bear! or meth head.