Handgun Energy: Interesting Paper

[WrongHanded]

Okay, I got too interested about where the energy from a handgun bullet actually goes. Apparently it's been studied a bit and two PHDs compiled some 'Scientific Evidence for Hydrostatic Shock', which does include information regarding handguns and remote damage to the nervous system. It can be downloaded in PDF form here:

https://www.researchgate.net/publication/1916018_Scientific_Evidence_for_Hydrostatic_Shock

But they also have a paper entitled 'The Ballistic Pressure Wave Theory of Handgun Bullet Incapacitation' which is similar but can be found here:

https://www.google.com/url?sa=t&sou...FjAAegQIBhAC&usg=AOvVaw17A2IwCoOj1-tqNYkiV28-

Very interesting stuff. And it might explain the fabled success of the 125gr HP .357 Magnum. I mean...maybe. Take a look and see what you make it.

 

[SharpDog]

Quickly glancing over the PDF in the google link (yay pictures ) I can see:

1. Figure 3 very roughly agrees with the general stopping power data in other studies.
2. Figure 1 seems to indicate that it will take at least 5 seconds to incapacitate by hydrostatic pressure wave.

 

[WrongHanded]

Quickly glancing over the PDF in the google link (yay pictures ) I can see:

1. Figure 3 very roughly agrees with the general stopping power data in other studies.
2. Figure 1 seems to indicate that it will take at least 5 seconds to incapacitate by hydrostatic pressure wave.

I see that too. Incapacitation is exactly what we want. But it still leaves the question of what happens in those 5 seconds between being shot, and incapacitation. Is it lights on for 4 seconds and lights off at 5? Or is it a fade to black type of deal? If only there were more answers.

 

[edwardware]

Good reading.

If you really want to get into it, the International Wound Ballistics Assoc journal is still available.

 

[danez71]

Okay, I got too interested about where the energy from a handgun bullet actually goes. Apparently it's been studied a bit and two PHDs compiled some 'Scientific Evidence for Hydrostatic Shock', which does include information regarding handguns and remote damage to the nervous system. It can be downloaded in PDF form here:

https://www.researchgate.net/publication/1916018_Scientific_Evidence_for_Hydrostatic_Shock

But they also have a paper entitled 'The Ballistic Pressure Wave Theory of Handgun Bullet Incapacitation' which is similar but can be found here:

https://www.google.com/url?sa=t&sou...FjAAegQIBhAC&usg=AOvVaw17A2IwCoOj1-tqNYkiV28-

Very interesting stuff. And it might explain the fabled success of the 125gr HP .357 Magnum. I mean...maybe. Take a look and see what you make it.

Ohh nooo..... now you done did it.

 

[WrongHanded]

Ohh nooo..... now you done did it.

I'm honestly surprised this information isn't more widely known of, even if it's considered questionable. None of the studies referenced seem to be particularly recent.

 

[danez71]

It's known but largely discounted.

It's a real thing... but in context of common bullets, is it really?; I think that's the issue.

Personally, I dont think it plays a part in all but the rare of circumstances.

 

[WrongHanded]

It's known but largely discounted.

It's a real thing... but in context of common bullets, is it really?; I think that's the issue.

Personally, I dont think it plays a part in all but the rare of circumstances.

I think whether or not it plays a part may have a lot to do with how much energy is even available to begin with, and then how quickly that energy is delivered. I'd assume magnum level cartridges are responsible for only a small fraction of shootings involving a handgun. And what may or may not be going on neurologically, is probably hard to observe in a gun fight.

But reading it does suggest to me that kinetic energy in handgun cartridges can matter. Which is something I'd previously believed was a possibility, but had no data to support. And if that's the case, more powerful cartridge may have a little something extra going on for them as far as the potential for neurological discombobulation (so scientific, I know).

 

[sparkyv]

Thanks for the interesting reading material, WrongHanded and edwardware. I'm a data junkie, and this will keep me entertained for some time.

 

[Kleanbore]

This well known phenomenon has discussed here at length before. It was the crux of the debate between Ackley and Weatherby on the one hand and Keith on the other. It is covered in the FBI report on handgun wounding effectiveness.

We see if in the "temporary wound cavity", which is discussed in oith the FBI report and on the Speer/CCI video.

Ad we hear in both, we are told that the temporary wound cavity has no material effect until we get to bullet velocities that exceed those of handgun cartridges.

 

[Jim Watson]

Ad we hear in both, we are told that the temporary wound cavity has no material effect until we get to bullet velocities that exceed those of handgun cartridges.

There was a study in Sweden on game animals, not felons, that concluded the "pulsatile cavern" did not become a factor until about the velocity of the 6.5x55 Mauser. What a coinkydinky that it favored their national cartridge.

 

[WrongHanded]

Ad we hear in both, we are told that the temporary wound cavity has no material effect until we get to bullet velocities that exceed those of handgun cartridges.

As far as tissue shearing, I believe that is true. But that's not what the papers are about. They're about neurological trauma. It's all right there for you to read. They are claiming that at energy levels possible from handguns, this type of trauma can and has occured.

This well known phenomenon has discussed here at length before.

Well known, and apparently largely ignored or even denied, based on many of the threads I've read on this forum about handgun cartridge efficacy since joining the forum. Many people have flat out denied that kinetic energy can play any role besides servicing penetration and expansion. And they have denied it as if it were a flat out stone cold fact. These papers say otherwise. So what amazes me is how easily people can deny the potential of this type of effect, and yet it happens constantly even though it's "well known" as you put it.

 

[Kleanbore]

s far as tissue shearing, I believe that is true. But that's not what the papers are about. They're about neurological trauma. It's all right there for you to read. They are claiming that at energy levels possible from handguns, this type of trauma can and has occured.

One more time: the FBI tells us that the temporary cavity----which is the very manifestation of the pressure wave--does not effect a physical stop.

Well known, and apparently largely ignored or even denied, based on many of the threads I've read on this forum about handgun cartridge efficacy since joining the forum.

Handgun is the key word here.

Many people have flat out denied that kinetic energy can play any role besides servicing penetration and expansion.

In the discussion of handgun cartridges, yes.

And they have denied it as if it were a flat out stone cold fact.

No, they have cited undisputed medial opinion from medical experts,

These papers say otherwise.

For high velocity projectiles, yes.

These papers say otherwise. So what amazes me is how easily people can deny the potential of this type of effect, and yet it happens constantly .....

What "happens constantly", and under what circumstances?

.... though it's "well known" as you put it.

Jack O'Connor discussed the subject in his writings about hunting with high velocity rifles at least as long ago as 1944.

 

[WrongHanded]

One more time: the FBI tells us that the temporary cavity----which is the very manifestation of the pressure wave--does not effect a physical stop.

Handgun is the key word here.

In the discussion of handgun cartridges, yes.

No, they have cited undisputed medial opinion from medical experts,

For high velocity projectiles, yes.

What "happens constantly", and under what circumstances?

Jack O'Connor discussed the subject in his writings about hunting with high velocity rifles at least as long ago as 1944.

Ah, you know the whole FBI thing is getting over-played in these discussions. Their feelings on the subject and previous studies of this very topic were address in one of the papers. Maybe you should go read them.

If you want to argue that the subject of these papers is false, you can argue it with someone else. I'm tired of listening to closed-minded rhetoric.

 

[Kleanbore]

Their feelings on the subject and previous studies of this very topic were address in one of the papers. Maybe you should go read them.

I have, and this is not the first time. I see their statements regarding alleged falsehoods and errors in prior studies, but no basis for support . I see hypotheses that are interesting--but no convincing substantiation.

The subject of pressure wave spikes on the CNS have been discussed on these pages before. I would never discount that effect. The problem is that the pressure dissipates rapidly with distance from where the wave is propagated. If we place a handgun-velocity wound close enough to the brain to have a material effect, we will also have significant tissue damage to the brain and/or spinal cord, and the subject becomes moot.

If you want to argue that the subject of these papers is false....

I do not. But I see no objective substantiation of the claim that low velocity bullets create dynamic pressure waves of sufficient magnitude to have a meaningful impact.

Keep in mind that the human body is extremely complex; it is not a block of ballistic gel. Each wound in each body will have a different effect. The FBI specification represents an attempt to cover the bases in those variations--and in what kind of barriers may be encountered. The velocity threshold about which we hear when temporary cavities are discussed is not a very scientific observation, either.

Keep in mind also that the experts at Speer/CCI and the other developers not only work with the FBI Training Academy--they also receive and analyze reports from the field.

Those who do not work in medical fields who would spend their time analyzing studies of wounding effects may find it interesting, but not very productive.

I know something about physics and something about materials properties, but I'll leave the subject of forensic medicine to others.

 

[WrongHanded]

I have, and this is not the first time. I see their statements regarding alleged falsehoods and errors in prior studies, but no basis for support . I see hypotheses that are interesting--but no convincing substantiation.

The subject of pressure wave spikes on the CNS have been discussed on these pages before. I would never discount that effect. The problem is that the pressure dissipates rapidly with distance from where the wave is propagated. If we place a handgun-velocity wound close enough to the brain to have a material effect, we will also have significant tissue damage to the brain and/or spinal cord, and the subject becomes moot.

I do not. But I see no objective substantiation of the claim that low velocity bullets create dynamic pressure waves of sufficient magnitude to have a meaningful impact.

Keep in mind that the human body is extremely complex; it is not a block of ballistic gel. Each wound in each body will have a different effect. The FBI specification represents an attempt to cover the bases in those variations--and in what kind of barriers may be encountered. The velocity threshold about which we hear when temporary cavities are discussed is not a very scientific observation, either.

Keep in mind also that the experts at Speer/CCI and the other developers not only work with the FBI Training Academy--they also receive and analyze reports from the field.

Those who do not work in medical fields who would spend their time analyzing studies of wounding effects may find it interesting, but not very productive.

I know something about physics and something about materials properties, but I'll leave the subject of forensic medicine to others.

Well, what can I tell you if you already know everything. Clearly you must be right. Because the FBI said. Two PHDs who are also West Point graduates must just be wrong. I gotcha. Every study that they have reviewed must also be wrong or faulty in some way. I'm sure the FBI (a well known center of scientific research) have conducted multiple in-depth studies on this subject, and thoroughly disproven it. It'd be nice to see those studies that the great bureaucratic minds at the FBI have produced.

I'm not trying to suggest that these effects are likely with a handgun, only that it seems they are possible. Do you flat out disagree that significant detrimental neurological disruption from the pressure wave effect of a temporary cavity is even possible?

 

[murf]

most of this is opinion since the human body structure is so complex. no need to rail at "he said, she said" dialog. also, all experts are idiots and that goes double for self-proclaimed ones. and, for a final cliche, everyone has an agenda and it's not yours.

stay cool,

murf

 

[WrongHanded]

most of this is opinion since the human body structure is so complex.

Absolutely murf. And the comparison and contrast between the physiology of test animals and humans will be where the goal posts move to next.

It's unfortunate that a person can't simply look at this information and say, "Hmmm, well maybe there's something to that. I'll bear it in mind."

 

[Kleanbore]

Two PHDs who are also West Point graduates must just be wrong. I gotcha.

I hate to say it, but I was not very impressed with either one of them.

I'm sure the FBI (a well known center of scientific research)....

Do you know the sources of the medical opinions that the FBI Training Academy used as a basis for their conclusions?

....have conducted multiple in-depth studies on this subject,

Yep.

and thoroughly disproven it.

Disproven what? Why?

It'd be nice to see those studies that the great bureaucratic minds at the FBI have produced.

Go get them.

I'm not trying to suggest that these effects are likely with a handgun, only that it seems they are possible

Sure. But how significant might they be?

Do you flat out disagree that significant detrimental neurological disruption from the pressure wave effect of a temporary cavity is even possible?

Of course not. It has been understood for decades.

Again, the human body is extremely complex, and every wound in every person is different. A vast body of research involving large amounts of field data, have been used to develop performance expectations for service handgun ammunition that will generally suffice. For the FBI and their law enforcement partners, one set of specifications exists; it has been adopted by every civilian agency of the Federal Government. The US military uses another. Civilians may choose sill others--I'm not hard over on the barrier requirements for my defensive use.

One might wonder why a block of gelatin shakes when it is penetrated, and one might wonder about the possible brief interruption of neurological signals. That's fine. Bu so far, no one has come up with any reason why these things should impact handgun ammunition design.

If it happens, I'm sure the folks at Speer /CCI will fell us about it.

 

[WrongHanded]

If it happens, I'm sure the folks at Speer /CCI will fell us about it.

I'm not going to bother responding point by point to most of what you wrote. Regardless of how this thread ends, you will continue to believe what you believe, and I honestly don't care either way. Although I do find it impressive that you can admit you believe this effect can occur, and then marginalize the potential immediately afterwards even though there's apparently not enough evidence.

But I'll say a couple things on this point. I think you put far too much faith in the people at Speer/CCI. They are responding to a market, which has already (thanks to the FBI) narrowly defined the design scope of defensive handgun ammunition. They will design to meet the demands of that market.

There's no particular reason for the FBI to consider the potential for what is discussed in these papers, because their agents have already proven they can't handle cartridges powerful enough to come close to reliable creating incapacitation via this means. Even admitting that it occurs would mean a whole bunch of questioning and pressure to try and incorporate it into there weapons systems. Why would they want that kind of mess. And as they (and the market they create) are the driving force behind service cartridge design and advancement, it seems easiest for them to continue to deny the possibility. That's politics, not science.

Sure. But how significant might they be?

That's exactly the point of the thread. How significant might these effects be? You can look at it from many different perspectives. The skeptic would say, until it's proven I'll ignore the potential. The optimist would say, I should get a gun chambered in a more powerful cartridge to make use of this effect. The realist would say, well it's nice to know that extra energy might be useful, so maybe I won't step down to a less powerful cartridge just yet.

And then perhaps we might discuss the potential of this effect and how it might be beneficial, rather than saying "well the FBI said......"

Or perhaps we could just let others read it and make up their own minds as to how relevant the information is to them.

 

[fxvr5]

The optimist would say, I should get a gun chambered in a more powerful cartridge to make use of this effect.

Which are these more powerful cartridges of which you speak?

 

[fxvr5]

I hate to say it, but I was not very impressed with either one of them.

Can you articulate what it was that did not impress you, and why, therefore their results might not have merit? Thanks.

 

[WrongHanded]

Which are these more powerful cartridges of which you speak?

I hadn't considered any threshold beyond the one they had produced of 500lbs with 12" penetration (I presume into ballistic gel) or the 700lbs with 14" penetration. So I'd suppose to meet their threshold one would have to find a cartridge load and gun combination to achieve that threshold value. I'd have to look at the papers again to get any more specific on those details.

But if someone were to try and get close to those numbers with reasonable common cartridges, one might include the .357 magnum and 10mm with the most appropriate loads. The .357 Sig being slightly less powerful, would likely not make in unless ammunition selection were very specific. The .40 again, likely marginal with only the lightest projectiles that would expand extremely rapidly. Making FBI minimum penetration whilst still dumping the energy quickly enough to create the 500PSI (I think that was the value) pressure wave, is a balance that seems it would be hard to strike with the latter two cartridges.

Then we get into compromises, such as the percentage chance of incapacitation. Or not full incapacitation, but maybe enough effect to be detrimental to control of motor function. An area of effect that is even less clear.

 

[Kleanbore]

you will continue to believe what you believe,

I believe that a handgun can succeed or fail in effecting physical stops, and that there are a large number of variables involved.

Although I do find it impressive that you can admit you believe this effect can occur,

there is substantial evidence that the effect is material when using high intensity rifle rounds.

and then marginalize the potential immediately afterwards even though there's apparently not enough evidence.

I have not yet seen persuasive evidence to the effect that the effect, though it may exist, is material when using handgun rounds.

But I do not care what causes an attacker to be disabled, as long as he is.

There's no particular reason for the FBI to... because their agents have already proven they can't handle cartridges....

That assertion shows a complete misunderstanding on your part of what is involved in the "handling" of a handgun in rapidly unfolding defensive encountesr, and of the underlying physics that impacts the rapidity of controlled fire for anyone.

By the way, the FBI recommendation was for "agents and our law enforcement partners".

...powerful enough to come close to reliable creating incapacitation via this means

Not only the FBI data, but also, substantial field data collected since the 9mm became widely adopted, have shown the 9mm to be very "reliable creating incapacitation".

Why would they want that kind of mess. And as they (and the market they create) are the driving force behind service cartridge design and advancement, it seems easiest for them to continue to deny the possibility. That's politics, not science.

Their analyses and conclusions, which are carefully and extensively peer reviewed, which are based on very voluminous data, and which reflect the consensus of quite a number of people, have yet to be shown to be invalid in the field.

And the opportunity to do so has now existed for some years.

 

[CapnMac]

Do you flat out disagree that significant detrimental neurological disruption from the pressure wave effect of a temporary cavity is even possible?

Ok, let's consider this in the specific rather than the abstract.

Let's examine the human corpus. Where, precisely are we likely to see a temporary wound cavity.. The torso is unlikely as the ribs introduce mitigating factors (constraining the tissue for one). The other issue being that the primary "filling" of the torso are the lungs, which are 80% air. Air is unlikely to create much of a temporary cavity.

The limbs are generally not going to have enough tissue mass to have much of a temporary cavity,either, as they are primarily muscle tissue encapsulating solid bone. There's that distance to CNS, issue, too.

What that leaves us with is the abdomen. Which as any examination of a gut pile will tell a person is a mass of varying density tissue. Now, hit one of the major arteries, and you'll get incapacitation--but through exsanguination.
The distance of the abdomen to the CNS is probably the crux of the delay noted in the report. But, if we look at specific organs of the abdomen, liver, pancreas, spleen, those are dense, glandular things that are not going to stretch uniformly into temporary cavities. And direct hits to those are like to to cause exsanguination, not neurological trauma. Which leaves us, really only with the intestines and stomach--and there's plenty of air in those, too. But they are going to be the one organ most likely to have a temporary cavity.

Shooting people in the guts is probably sub-ideal on several levels.