Yeah that's all well and good and yes a 45 would be optimal, however nobody wants to carry a gallon of milk in their waistband! I could turn that story around and say a Meth head that took 18 rounds from a 9mm could just as easily grab that 45 straight from your hand. I think it breaks down like this, having a gun isn't the end all gonna save you tool, however it ups your chances of survival. Everything after that depends on your will, physical ability, who your up against and so on. A smaller, weaker man might feel more comfortable with a 45 and be able to take that Meth head down, yet maybe I could do the same thing with a 22lr simply because I'm bigger and was able to wrestle him into a position that made my shot count, I.e neck or head