I've never had to fire a gun in self defense. So whatever I think would be good for the job would be, mmmm....presumptuous, since nothing has ever had to stand up to the test of actual experience. I would guess that the most failure prone part of the formula would be the inexperience of the defender who has never been-there-and-done-that. It is so ingrained in us to not harm others that, if we really had to, for the first time, we might be highly prone to fail. I suppose those with actual experience who survived would probably be better prepared mentally, even with a 22 rimfire, to come out on top of a bad situation. I keep my Vaquero loaded with my main woods load, 255 grain cast bullets at 1075 fps. Probably not the best for home defense against a violent intruder, but at least I'm familiar with it. And I don't feel the need to go around armed for trouble where I live, so it's put away where only I would find it. I only open carry in the woods. If society in these parts were to substantially degrade, perhaps I would change my carry habits.