One-Shot Incapacitation by Handgun Compared

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How can .32 caliber have the highest one-shot incapacitation rate among handgun calibers listed? Should I trade in all my handguns for .32s?;)

We CAN'T say how this is so, because we don't have the full "study".

If we had the full study, showing all the data, sources of data, demographics, etc, then we might be able to make an educated assumption.

But we don't.

Maybe most of the data came from rural areas with elderly people. Maybe it's cherry picked. Maybe the sources were biased.

Heck, maybe it's all just made up.

Regardless, I don't think you need to be offloading all your handguns just yet.

But if you feel you MUST... I'll be happy to take them off your hands!
 
I think @JTQ makes a good point. We have a huge amount of information regarding calibers for +/-200 pound game animals, and while the analogue isn't perfect, it may be the best thing we've got. And .32 caliber handgun cartridges aren't anywhere on that list.
 
I don't know where they got this table but it seems wrong. How can .32 caliber have the highest one-shot incapacitation rate among handgun calibers listed? Should I trade in all my handguns for .32s?;)
View attachment 1077617
Source: Expand First Post and Scroll Down.

So the person who posted the chart explains it this way,


If you're going to look at a chart that was lifted from some other work, it may pay to go back to the source and look at more than a conveniently copied snapshot of a small piece of the work.

Here's a link to a source where you can read the info posted by the author of the Greg Ellifritz study:
https://www.buckeyefirearms.org/alternate-look-handgun-stopping-power

Now, context is pretty important, but so is looking at all the data and statistics he developed.

For example, in his project he was able to come up with 25 people who were shot by .32's, meaning both .32ACP and .32Long.

.32 (both .32 Long and .32 ACP)
# of people shot - 25
# of hits - 38
% of hits that were fatal - 21%
Average number of rounds until incapacitation - 1.52
% of people who were not incapacitated - 40%
One-shot-stop % - 40%
Accuracy (head and torso hits) - 78%
% actually incapacitated by one shot (torso or head hit) - 72%

Browse through the rest of the chart where he lists the same statistical data for all the other calibers he studied. Look at the varying number of people involved for each caliber, and how the statistics would break down. Makes using just one type of calculated percentage and category about as useful and clear as mud. :)

He makes some interesting observations and comments in his article, and it's worth reading. Here are a couple snippets for review, though ...

I really would have liked to break it down by individual bullet type, but I didn't have enough data points to reach a level of statistical significance. Getting accurate data on nearly 1800 shootings was hard work. I couldn't imagine breaking it down farther than what I did here. I also believe the data for the .25, .32 and .44 magnum should be viewed with suspicion. I simply don't have enough data (in comparison to the other calibers) to draw an accurate comparison. I reported the data I have, but I really don't believe that a .32 ACP incapacitates people at a higher rate than the .45 ACP!
...
Another data piece that leads me to believe that the majority of commonly carried defensive rounds are similar in stopping power is the fact that all four have very similar failure rates. If you look at the percentage of shootings that did not result in incapacitation, the numbers are almost identical. The .38, 9mm, .40, and .45 all had failure rates of between 13% and 17%.
...
The lower caliber rounds (.22, .25, .32) had a failure rate that was roughly double that of the higher caliber rounds. The one-shot-stop percentage (where I considered all hits, anywhere on the body) trended generally higher as the round gets more powerful. This tells us a couple of things.
...
This study took me a long time and a lot of effort to complete. Despite the work it took, I'm glad I did it. The results I got from the study lead me to believe that there really isn't that much difference between most defensive handgun rounds and calibers. None is a death ray, but most work adequately...even the lowly .22s. I've stopped worrying about trying to find the "ultimate" bullet. There isn't one. And I've stopped feeling the need to strap on my .45 every time I leave the house out of fear that my 9mm doesn't have enough "stopping power." Folks, carry what you want. Caliber really isn't all that important.

One of the important conclusions he derived from his project?

Caliber really isn't all that important. :D

Or, looked at from another perspective ... TANSTAAFL

How very unsurprising. ;)



 
Whether or not a person will likely be incapacitated immediately (and that's what is important) is a function of a number of variables. If we could eliminate differences in physiological and psychological factors, we would settle on what in the body is damaged, and to some extent, how badly.

That would depend primarily upon the following:
  • The precise point of entry of the bullet
  • The entry angle
  • Penetration
  • Expanded diameter
We are told that for premium JHP bullets between .38 and .45, the last item is the least important.

The human body is so complex, and compared to the bullet, so large, that in practice, differences among the above factors between one shooting incident and the next will result in great differences in the results.

For that reason, trying to differentiate among different handgun cartridges by looking at actual statistics is pretty much a waste of time.
 
Whether or not a person will likely be incapacitated immediately (and that's what is important) is a function of a number of variables. If we could eliminate differences in physiological and psychological factors, we would settle on what in the body is damaged, and to some extent, how badly.

That would depend primarily upon the following:
  • The precise point of entry of the bullet
  • The entry angle
  • Penetration
  • Expanded diameter
We are told that for premium JHP bullets between .38 and .45, the last item is the least important.

The human body is so complex, and compared to the bullet, so large, that in practice, differences among the above factors between one shooting incident and the next will result in great differences in the results.

For that reason, trying to differentiate among different handgun cartridges by looking at actual statistics is pretty much a waste of time.

This - the fundamental problem with the Marshall and Sanow data is that shootings are all highly individual and there are too many variables involved to narrow it down to just bullet caliber as deterministic of the outcomes, even if the data was available for review and was consistently collected and of consistent quality. The Marshall and Sanow 'data' is less data than a large-ish collection of anecdotes.
 
For that reason, trying to differentiate among different handgun cartridges by looking at actual statistics is pretty much a waste of time.

Which takes us back to the old adage, carry the biggest caliber you can comfortably carry and handle.

Of course, unless the other guy has a gun too, you double tap and run for it. So a smaller caliber might be effective to extricate yourself from the situation.

The other factor is where you are going. If you are going to a really bad area, more and bigger arms. If you are in a good area, a vest pocket 32 might just do.
 
Everyone always seems to focus on the expanded diameter of the recovered projectiles, instead of the frontal area (radius squared x pi) x the depth of penetration. The current generation of “experts” claim that for handguns, only the permanent crush cavity matters. Since all defensive ammo is tweaked to the FBI criteria, they all will penetrate 12-18”. So for a non Central Nervous System hit, the largest diameter expanded round will be the most effective, on average.

As far as stats goes, the 32 in Ellifritz’s data is just below the threshold for being valid in the number of people shot, and way below the threshold for being valid in the number rounds shot.

I suspect that if the 32 had a statistically valid number of shootings / hits, it would have much lower effectiveness numbers, based on a lack of expanding projectiles that penetrate adequately.
 
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If you're going to look at a chart that was lifted from some other work, it may pay to go back to the source and look at more than a conveniently copied snapshot of a small piece of the work.

Excellent post you have, there.

I was the CMEO (Command Managed Equal Opportunity Officer) on one of my submarines many years ago. Consider doing a command climate survey each year on a crew of 150 or fewer people and trying to get any meaningful statistics from it.

When I did it, we didn't have any software to automatically tally the information up... we did it ourselves. So lack of consistency across the fleet you could get variations just from that.

But consider how the answers related to race might look in a small crew of 150 where black people might compose 30 of the crew, and Asian people might 3, and the rest white. Drawing meaningful statistics from such a small crew is challenging, to say the least.

Unfortunately, those who aren't experienced in doing this very much don't understand how a single complaint from a single person in a small group can provide skewed information.

To be sure, Navy wide it's a different matter because the raw data gets fed up the chain of command to eventually encompass the entire Navy. But even then, statistics can be skewed when trying to get something meaningful. An individual command, of small size, can legitimately be an excellent EO command, yet have statistics which show otherwise compared to the entire fleet.

In general, the larger the sample size, the better off you are with statistics.

Especially when dealing with different calibers. Any small sampling of one or more groups of calibers skews everything.
 
I think @JTQ makes a good point. We have a huge amount of information regarding calibers for +/-200 pound game animals, and while the analogue isn't perfect, it may be the best thing we've got. And .32 caliber handgun cartridges aren't anywhere on that list.

Yeah, that is a really good point. There are only two problems with it.

1: Because the FBI cares about potential over penetration, now we all do. Whereas hunters typically want a pass through shot if possible, for a faster drop in blood pressure, and therefore incapacitation. There are some great arguments against over penetration, but in some circles it's been blown way out of proportion.

2: Unlike hunters, those primarily interested in self defense want the smallest lightest and lowest recoiling cartridge (and also usually handgun) in which they can feel a sense of confidence. I never got the impression handgun hunters are constantly striving to find the weakest possible cartridge and loading that will still "get the job done".
 
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I don’t doubt that the .32 gets used a bunch in Europe. Any imported .32 ACP ammo always seemed hotter then American stuff. I have also watched videos and read plenty that makes a good case for the .32 family of cartridges not to be brushed aside or down played. But for it to be on top I am just not believing it.

No way to know this but it sounds like data to support the new thing of .30 Carry. Maybe some clever marketing?
 
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I have a CZ-70 that runs .32 ACP. It is about the size of a compact S&W EZ or something like that small size, but not the smallest. Like a Walther PP kind of size. It is similar in nrg to a .22 LR from a rifle. That's not Thor's hammer, but I don't care. I shoot it well, it is all steel and easier to carry than a revolver, and way easier to shoot than a 9mm of the same size, and I'm a believer in hitting your target over how big the firearm cartridge is. I like the thing and carry it sometimes, and my perspective is - if I can shoot well enough to hit consistently at 6" steel targets at 20 feet, I can brain someone at 5 or 10 feet, and I have 16 rounds which I can rattle off a lot faster than I can shoot 9mm, so - maybe if I get better at shooting I'll look at a sub compact 9mm, but they are not fun to shoot IMHO, and I'm mostly a hobbyist an have little/no interest in hearing damage, or tendon damage in my shooting hand. It is a hobby that is fun to me, target shooting, and if it saves me some day, great - if not, well - sometimes that's the breaks.

Look up the ballistics on Fiocci and S&B euro, 7.65 Browning .. which is .32 ACP, mostly the same, but they have a slight variation and is hotter. Run that through a 3.5 inch barrel like it was intended, and it is interesting.

I also carry an NAA Mini sometimes with .22 Mag, so - it is like being sort of armed, and that's better than not armed; a little better. I'd trade any handgun for a decent .22 rifle, semi-auto in a situation where I needed something. There's like no chance I'm going to miss, and you can really rattle off a lot of rounds fast. Load that thing with some high velocity hollow points, and - you are fast and accurate and dangerous if need be. Really, it comes down to who can get a hit or several hits first in a confrontation. What you hit them with, sure, it matters, but less than speed and accuracy IMHO.
 
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It is my belief the caliber matters very little in the average self defense shooting. If one’s goal was to kill, especially ethically (hunting, obviously) it would matter much more. However, if the goal is to simply stop an attacker from attacking, then I really don’t believe caliber is commonly a determining factor in the outcome.

I freely admit I have no data or analysis to back up that position, its just a belief based on personal opinion and anecdotal evidence, at best.
 
Which takes us back to the old adage, carry the biggest caliber you can comfortably carry and handle.

Of course, unless the other guy has a gun too, you double tap and run for it. So a smaller caliber might be effective to extricate yourself from the situation.

The other factor is where you are going. If you are going to a really bad area, more and bigger arms. If you are in a good area, a vest pocket 32 might just do.
None of that holds water.
 
So the person who posted the chart explains. . .
That's not an explanation, it's a word salad of grammatically and statistically questionable gobldygook.

If the author's statistics are as confused as his English, disregard the whole as sordid affaire.
 
I know from hunting that you can shoot two of the same type of animal in very similar places and come out with different results. I also know that in human examples, what is or is not fatal is often the result of what medical treatment was received and how quickly. I know of a lot of one shot stops with various calibers that were non-fatal, non-incapacitating, and a few that didn't even hit the bad guy. Psychological stops are great when they happen, and they do happen, but are not very predictable.

A lot of these shot percentages are thrown out there like they mean something. However, virtually no two people are ever shot exactly the same way. Shot distances, angles, circumstance, bullet types, velocities, etc. are often quite varied. You can find accounts of people shot in the heart that survived, the survivors being fatally shot, had they not gotten the correct care fast enough. As such, they are not in the fatal category, which is really interesting. After all, how can caliber take into consideration the speed and skill of subsequent medical care? Many people may become incapacitated by a single shot, but is the incapacitation instant, quick, or maybe minutes or hours later.

The numbers are just a mathematical derivatives of generalized categories that fail to take in a lot of very relevant factors that influence the success of the impact of the shot on the intended target. As such, while the resultant numbers appear very precise and are heuristically interesting, they are also false precision. No doubt this is why the .32 appears to be a wonder caliber occupying a magical synergistic crossroads of a comparatively smaller caliber, lighter weight, reduced energy, moderate velocity, reduced to moderate penetration, etc.
 
I'm saving my time by not reading beyond the absurd OP chart or most of the subsequent posts.

There is plenty of real-life data that proves: To be sure the only way a handgun projectile of any caliber/cartridge can reliably stop a threat, it must sever (interrupt) the central nervous system! The data doesn't point to any specific cartridge/caliber but shot placement and penetration. Also, ER surgeons can verify that once projectile encounters flesh the path cannot be predicted.

FBI tables from recent studies detail this in terms of penetration and wound channel and damage specific to the central nervous system, spine and frontal cerebrum penetration.

Anything less is just a distraction!

"A handgun is that implement used to distract the threat in a way that you can get to your long gun so you can eliminate that threat"!

Active shooter scenario!
Choose one:
a) .32 hand gun
b) 5.56 M4 carbine

Smiles,
 
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I've been hit with a 32. Don't want to repeat the experience. It will break bones and leave a hole you can put your index finger in.
 
If you're going to look at a chart that was lifted from some other work, it may pay to go back to the source and look at more than a conveniently copied snapshot of a small piece of the work.

Here's a link to a source where you can read the info posted by the author of the Greg Ellifritz study:
https://www.buckeyefirearms.org/alternate-look-handgun-stopping-power

Now, context is pretty important, but so is looking at all the data and statistics he developed.

For example, in his project he was able to come up with 25 people who were shot by .32's, meaning both .32ACP and .32Long.

.32 (both .32 Long and .32 ACP)
# of people shot - 25
# of hits - 38
% of hits that were fatal - 21%
Average number of rounds until incapacitation - 1.52
% of people who were not incapacitated - 40%
One-shot-stop % - 40%
Accuracy (head and torso hits) - 78%
% actually incapacitated by one shot (torso or head hit) - 72%

Browse through the rest of the chart where he lists the same statistical data for all the other calibers he studied. Look at the varying number of people involved for each caliber, and how the statistics would break down. Makes using just one type of calculated percentage and category about as useful and clear as mud. :)

He makes some interesting observations and comments in his article, and it's worth reading. Here are a couple snippets for review, though ...

I really would have liked to break it down by individual bullet type, but I didn't have enough data points to reach a level of statistical significance. Getting accurate data on nearly 1800 shootings was hard work. I couldn't imagine breaking it down farther than what I did here. I also believe the data for the .25, .32 and .44 magnum should be viewed with suspicion. I simply don't have enough data (in comparison to the other calibers) to draw an accurate comparison. I reported the data I have, but I really don't believe that a .32 ACP incapacitates people at a higher rate than the .45 ACP!
...
Another data piece that leads me to believe that the majority of commonly carried defensive rounds are similar in stopping power is the fact that all four have very similar failure rates. If you look at the percentage of shootings that did not result in incapacitation, the numbers are almost identical. The .38, 9mm, .40, and .45 all had failure rates of between 13% and 17%.
...
The lower caliber rounds (.22, .25, .32) had a failure rate that was roughly double that of the higher caliber rounds. The one-shot-stop percentage (where I considered all hits, anywhere on the body) trended generally higher as the round gets more powerful. This tells us a couple of things.
...
This study took me a long time and a lot of effort to complete. Despite the work it took, I'm glad I did it. The results I got from the study lead me to believe that there really isn't that much difference between most defensive handgun rounds and calibers. None is a death ray, but most work adequately...even the lowly .22s. I've stopped worrying about trying to find the "ultimate" bullet. There isn't one. And I've stopped feeling the need to strap on my .45 every time I leave the house out of fear that my 9mm doesn't have enough "stopping power." Folks, carry what you want. Caliber really isn't all that important.

One of the important conclusions he derived from his project?

Caliber really isn't all that important. :D

Or, looked at from another perspective ... TANSTAAFL

How very unsurprising. ;)

Well I guess one could conclude that shot placement is far more important than caliber. However, the smaller the caliber, the more precise that shot placement must be to be effective.
 
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