Adding more marginal statiscal guestimates doesn't make anything clearer.
So are you saying that no one has any idea how many shots of .38Spl it takes to incapacitate someone, on average, or are you just saying that you don't like the statistics I'm quoting because they provide an undesirable answer when calculating the probability of success?
I think that the outcome of a couple hundred shootings using .38Spl (the study was based on 199 shootings with that caliber) provides some basic insight into the problem even if the exact number might not be exactly 2 shots and even though any given scenario might differ from the average based on the variables and circumstances.
You asked for some statistics and I provided them. There are probably other sources if you don't like that source, and many of them can be located with an internet search just like I found that source. Not that it's really a stretch to start with the assumption that 2 rounds should be considered a decent rough estimate of the number of rounds out of a service caliber pistol required for incapacitation. The double-tap wasn't just dreamed up because someone's favorite number was "2".
So they default to a worse case scenario that, coincidentally, matches up really nicely to the newest and most popular police and competition firearms.
It's not that anyone is defaulting to a worst case scenario, it's that if you want to talk about the relative merits of pistols for defensive use, and you don't intend to focus on psychological stops, the focus is on incapacitation.
As I said, we can talk about what gun is good for psychological stops, but it's pretty pointless in the context of gun selection since psychological stops are about a person being frightened into giving up/fleeing. And that's not got much to do with accuracy, capacity or terminal effect.
If we want to get past talking about psychological stops then we start talking about incapacitation. Not because incapacitating the attacker(s) is a likely necessity in a typical self-defense scenario but because we are interested in talking about the scenarios where the gun choice might make a difference, as opposed to the scenarios where the attacker flees/surrenders out of fear and the gun choice is essentially irrelevant.
No one is saying that a snubbie is sufficient for every possible defense situation...
Of course--no gun is.
And they feel they have the math to prove it.
The math provides an accurate answer to the question posed, given the listed assumptions.
The thread provides a very thorough explanation of the question posed and the listed assumptions.
http://www.thehighroad.org/showthread.php?t=665883
Does it tell you everything you need to know about defensive weapon selection? Hardly, and if you read the thread it doesn't claim to. In fact, at one point I made the comment that: "The results provide a limited insight into one very narrowly defined aspect of handgun self-defense. They are not intended to, nor has any claim been made that they fully and accurately replicate all the intricacies of a real-world gunfight."
You had said previously that 5 shots wasn't enough, but 6 may be based on a John's formula from another thread. But that formula is completely based on an assumption that police hit rates are applicable, even though defense shooters do not shoot like police do.
Actually the OP in that thread provides the means to determine the probability of making 4 hits (2 on each of 2 opponents) for hit rates from 10% to 90%. For example, if you think that a 70% hit rate is more realistic then you can use the plots to determine that the chance of making 4 hits before a 5 shot gun is empty is a little better than 50% if you can make a hit 7 out of 10 times you pull the trigger.
I think that this is what made some really stop and think. If you can make hits more than twice as consistently as the average cop (using the 30% figure for the average cop) then you still have only a little better than even odds of making 4 hits before the gun runs dry.
Does that mean that 5 shots is too few? It's not that simple.
What it means is the following: If you would like the capability to be able to incapacitate 2 attackers and feel that 2 hits or more per attacker will likely be required and that a hit rate of 70% or less is reasonable, then you might want to rethink choosing a 5 shot gun. Because at best, the chances of making that work with 5 shots is a little better than 50/50. Drop the hit rate to 60% and the chances of succeeding are 1 out of 3. At 50% hit rate the chances of making all 4 hits are 1 out of 5.
But let's say that you reasonably believe you will be able to make 90% hits in a real-world shooting and won't ever have to incapacitate more than 2 attackers. Then picking a 5 shot gun could make sense given that the odds of succeeding with those assumptions would be a little better than 9 out of 10.
The math provides the information and then each person can decide what kind of odds they think are a reasonable risk given their personal limitations and their assessment of what scenarios they might face. That's what it's all about--deciding what kind of risk is acceptable. All the calculation provides is some sort of a basis for making that decision.
So is 5 shots too few? Most people believe that 0 shots is enough, given that very few people carry handguns on a regular basis. But if one assumes, for example, that a 50% hit rate is reasonable and a defender might encounter 2 determined attackers, each requiring at least 2 hits to neutralize, then 5 shots is only enough if a success rate of 1 in 5 is acceptable.
