Most shots fired in anger miss. I was surprised to learn just how consistent the pattern is. Various explanations have been put forth. One is the fright factor inherent in bullets traveling the wrong way, toward you not away. Some people have supposed, in addition, that most of us have a deep-seated subconscious objection to shooting someone, thus a built-in tendency to miss. But whatever the cause, a whole lot of bullets get launched that do not hit their human targets.
http://shootery.blogspot.com/2013/01/why-private-citizens-really-do-need.html
True. I'd surmise that the reason is that the first time is awkward... for many things! The first time you actually shoot in self-defense, the rush of adrenaline and all makes your limbs move a bit on their own, and overtaking your decision process. You tend to shoot early, before being on target, or without proper coordination. Afterwards you can debrief yourself, and hopefully the next time you do better. Until perhaps you can keep your cool and master the situation. Of course, this habituation does not happen in the vast majority of armed encounters for ordinary citizens... So yes, more shots than needed are fired, and they don't all find their mark.
CapnMac, I did not run, I'm in the boondocks and could just give a look once in a while...
This said, it's interesting to see all the various opinions and arguments in this thread, drawn from different experiences or expectations...
I do not advocate a minimalist approach to self-defense. Rather, a proper assessment of the realistic threat anyone faces in his own circumstances, which can vary depending on time and location.
I think that for many, the threat does not necessitate three dozens rounds to sort out things, and that one would be served just as well with a single-stack 8 to 10 rounder than with a bulkier and heavier tool. Matters of personal preferences, but "whatever the rest of the pack does, especially on Youtube" should not be part of the decision process when selecting a gun for carry.
In Westgate Mall scenarii, 18 rounds are little and you'd wish you had a carbine or rifle with 3-4 magazines. I know the Westgate, shopped and had snacks there with my family. I also spend time almost every day in similar locations, which are marked targets for a variety of miscreants ready to die in order to kill you. Some of those locations have actually been bombed already... I still go there because we're not about to allow bastards to keep us from living our lives. Still, my favor goes to a 9-10 rounds single stack, with a couple of reloads if going to potential "high risk" areas.
Around home or in the street, that same gun, even without reload. Plain vanilla robbers strongly object to being shot at, and tend to decamp in a hurry when this happens - at least our local breed.
When in the bush in locations where the threat is armed bands of cattle raiders and various semi-rebel/bandits, who use mostly AKs (or G3s if they come from the Kenyan side) we rarely move in groups less than six strong, and our usual complement is around 10 men, 10-12 rifles - a couple of bolt actions and mainly AKs. A GPMG when the weather forecast is cloudy with possible showers. Again, carrying for the assessed threat...
As an aside, someone mentioned that animals do not present a threat unless they are in immediate proximity. Well, yes, but... When you chase a wounded animal in long grass or thick bush, often the distance of engagement is counted in paces. Things wait until you almost step on them, then jump on you from nowhere, with just a rustling of grass or branches to give you a warning. When you actually see the incoming train, it can be as close as one or two rifle lengths. And people in these circumstances still manage to pull aimed brain shots - not MOA aimed, but in-the-ball aimed. That's why I say that aimed CNS shots are better than multiple center-of-mass shots - and possible. Even a straight-through heart shot can leave an assailant with enough reserves to pump a full magazine into you.