Posted by Gun Master: The charts he [Kleanbore] uses as "documentation" seem to have no factual information, and are based on unfounded assumptions and formulas for number of rounds needed, possibilities of hits, number of assailants, etc., et al, ad infinitum.
I do not use those charts as "documentation".
They are simply an analysis. You can vary the assumptions to your heart's content and run the numbers yourself.
The charts were developed by JohnKSa, who is on the staff at
The Firing Line and who is a member here, for his own purposes during a discussion on TFL similar to this one, and he found them eye opening. So did I.
And that's all they really are. They put things in perspective. They show the range of possibilities.
He assumed a 30% hit ratio. Don't like it? Use another number. John's charts show the effect of varying the assumption, as long as you stick with four hits in total. But you could vary that, too, if you want to. And there are data to support the idea that 30% is at least
reasonable.
But one could validate hit rates through some extensive FoF simulation, if one really wanted to have an idea about what one might expect.
He assumed the need to hit each assailant twice. The number may be one, two, three, four...Try any number you like. Frankly, I don't have any idea at all about how to choose a good number. But I should think that two would not represent a worst case assumption. What do you think?
He assumed that the defender would stop shooting after two hits. Personally, I think that that's a best case assumption. Could you stop then? Would you? I can easily imagine firing four shots in rapid succession, as one sees on televised Tueller drill exercises.
He assumed two assailants. The likelihood of that is supported by data that have been provided in other discussions here. But there might be one attacker. John addressed that possibility also.
He also assumed that a second assailant would have to be shot. That may be worst case, because the second one may turn tail. But he may not realize what has happened, or he may have no way to escape without the defender's car, or he may be so close that he feels that pressing the attack represents his best chance, or he may be using meth, and the defender may have to shoot him, too. What would
you prepare for?
Another assumption he made was that the defender would survive to be able to use the ammunition in his gun. You could model different assumptions on that count, but it would significantly complicate the analysis. I think it reasonable that the defender's survival chances would decline very significantly before he could get off 17 shots, for example.
All of that was discussed ad nauseum in the thread to which strambo provided the link, and in several other long discussions as well, here and on TFL. This is a perennial subject.
Choose your own assumptions and run the numbers yourself, if you don't like John's charts.
Then make your own conclusions.
I ended up carrying 10+1, but mind you, I did not base that on any expectation of having to fire 11 shots. It's just that I like a margin of safety, and that I do not like the idea of being left with an empty gun or standing around reloading.