Calm down. We're just having a discussion here.
To ThePanda:
You're right about one thing. You're way over the top. You can express your opinion without making it insulting.
While it is not ethical to shoot people, and possibly not goats either, this was tested on goats in Europe. I never suggested shooting people for tests, nor goats either, but it's been done to goats. It's also been done to cattle in slaughter houses. Read Ayoob's book(s). I don't think steers tell us much about people though.
You are correct that "one shot stopping power" can't simply be multiplied by the number of shots to get an accurate number. It doesn't need to be accurate. If it's way over 100% that's good enough for me. If you don't like it, then figure it some other way, or don't figure it.
You are entirely mistaken in several areas. Most notably your comment that each preceding shot has no affect on the outcome of following shots. Clearly, getting shot multiple times is more physically tramatic than once. Anyone knows that.
Each shot takes a toll, even if it doesn't incapacitate by itself. This adds up. Use your common sense. No, maybe we can't put an accurate number to it, but it certainly adds up. Maybe we don't know exactly what it adds up to statistically, but we know it adds up to something larger than one shot by itself. That's common sense. I've also learned this by observation and experience as I'll explain below.
I won't even address your comment about each shot being LESS likely to stop an attacker than the preceding shots. That isn't even worth my time.
As for your statement that a 40% one shot stop possibility would always be 40% for each shot fired, no matter how many shots fired... Let me politely point out that if you get punched in the nose 3 times, it's more likely to put you down than once punch. Maybe not 3 times more likely, or maybe more than 3 times. I don't know. But certainly injuries add up. Same with bullets.
My grandfather used to poach deer with a .22 Magnum semi-auto. He said 3 quick shots always dropped them. I doubt one shot would have. He proved a .22 Magnum is a consistant 3 shot stopper on deer. Here is an interesting parallel. One chest shot with a .22 Mag would not likely put down a deer, but 3 always did over many years of poaching. What does this suggest? Could it suggest that three shots on target is more damaging than one? Mmm. Let's think about that.
I can tell you in detail about shooting possums with a .22 long rifle. No amount of shots would keep them from running off when using round nose bullets. With round nose I could only get about 5 or 7 in them before they'd run off. However, with hot loaded hollow points (stingers or yellow jackets) three chest shots would do it with fair consistency. Sometimes a 4th shot would be needed. Clearly one shot was not enough, but 3 or 4 was with hollow points. Multiple shots add up.
Statistically you can't simply multiply "one shot stop percentage" by number of shots to get an accurate total number. You are right about that. So what? It's a best guess. The best guess I can make without shooting goats multiple times. Hey, that's a good idea. Thanks.
No, I'm not really going to start shooting goats, but I really did take out those possums with a .22 and once with a bow and target arrows. Both required multiple shots
When "one shot stop percentage" is multiplied by number of shots, maybe it's really greater than the total, maybe less, maybe equal. No one knows. It's a guess. In my experience hunting possums, I found 3 shots is 3 times as damaging as one, if each shot gets enough penetration. That's the big "if".
If penetration not adequate, then no amount of shots will do it. If expansion is not adequate, then a lot of shots will do it, but I mean A LOT (more than 5). If penetration and/or expansion are borderline (almost decent), like a stinger .22 on a possum, then I have observed 3 shots to be approx 3 times as good as 1. With round nose .22 bullets, it took 10 shots or more, if I could corner them. Usually with round nose they'd get away because I wasn't fast enough to get more than 3-5 shots in them. That's why I stopped using round nose.
My feeling is this, a severely inadequate cartridge is still severely inadequate until you get about 10 well placed shots. By then an attacker could be carving his initials in your chest with a knife. However, a borderline cartridge (like .380) is probably enough with 2 or 3 shots. 9x18 has just enough edge over .380 that I think 2 shots would likely do it. A 3rd shot is still an option.
Of course the above only applies to an insane or enraged attacker. No sane person would charge any handgun, especially if they were already shot once. Any sane person would be stopped or running the other way. I think most attackers are sane and even the sight of a handgun will deter most. For a sane attacker, the mere sight of a gun would have stopping power.
By the way, that's why I like shiny nickel guns or stainless for day time carry. Besides being prettier, they look scarier to bad guys. At least I read that somewhere. Makes sense to me that a flashier gun attracts more attention, which MIGHT be more intimidating, which MIGHT make it unnecessary to fire a shot. For night carry, I prefer matte black or blue because I think stealth more important at night.
thepanda said:
I'll admit that I didn't read much of this post; I had to stop after reading one of the first statements in the first post. I believe the author of the statement was saying that a .32 ACP cartridge has "3 shot stop power" because it's "shot stop capability" was around 40% and this multiplied by 3 was well over 100%.
First of all, I have no idea where these "facts" are from our how they could possibly be accurately measured when one considers the number of variables involved and the ethics of shooting other people for statistical purposes.
Second, the author's statistical reasoning is fundamentally flawed. Let us say that "shot stop capability" is an accurate measurement and the cartridge stops threats 40% of the time with one round. You cannot simply multiply this percentage by 3 to get 120%, which is over 100%, and assume the threat has been stopped. Using this same logic you could say that each individual round has a 60% chance of not stopping the threat, which multiplied by 2 equals 120% and therefore you could not possibly stop a threat with 2 rounds. Using this logic your odds of stopping the target would be 60% worse each time you fired! Obviously, using statistics in this manner does not work. Statistically, each bullet acts independently of the round before it. Each time the trigger is pulled and a round is fired, and assuming the "shot stop capability" is accurate, the round has a 40% chance of stopping the threat. It doesn't matter if you fire one or one hundred rounds, each round has a 40% chance of stopping the threat. Now, statistically, your odds of perpetually falling within that 60% range that does not stop the threat decreases the more you fire, but one cannot calculate these odds with simple multiplication.
Also, the concept of "shot stop capability" seems ridiculous to me. The ability of a round to stop a threat is GREATLY influenced on point of impact, age of threat, health of threat, windage, elevation, clothing, type of drugs the assailant is using, and millions of other variables. The simple fact that the threat is moving toward the shooter influences the effectiveness of each round by both creating an additional opposite force in the collision and reducing flight time of the projectile. Additionally, each shot that hits the threat changes the target's surface area and acceleration. Needless to say, an accurate "shot stop capability" would be difficult, if not impossible, to measure even if it weren't unethical to practice shooting people.
Anyway, my rant is over. Maybe it was a bit much considering I'm new around here and new to firearms in general, but I'm not new to statistics and physics. I just thought this information was worth clarifying. Happy reading!