The hydrostatic shock theory?

JohnKSa · Sep 18, 2011

Winfried,

Is this the book you refer to?

WOUND BALLISTICS

Editor in Chief: Colonel JAMES BOYD COATES, Jr., MC
Editor for Wound Ballistics: Major JAMES C. BEYER, MC

http://history.amedd.army.mil/booksdocs/wwii/woundblstcs/default.htm

Loosedhorse · Sep 18, 2011

It was wrong of me to respond harshly instead of taking the opportunity to be more constructive in how I addressed his comments. I will do better in the future.

I recognize the correctness of your words here, and admire them. I will try to take them as my example.

well-respected voices in the established community of terminal ballistics researchers that seem to be willing to speak out scathingly against anything that disagrees in the slightest respect with their pet theories

Agreed. I believe the biggest problem that has caused is the poor example it sets. It gives the impression that the way to "discuss" such issues is to dismiss the other's theory, and "explain" that the other is an idiot.

No. What I have tried to point out is that we don't know more than we know. We do not know enough to say that the Courtneys' BPW-causes-incapacitation theory is true...and so similarly, we don't know enough to say it's false. There often seems confusion on this point: lack of proof that something occurs is NOT the same as proof that it does not occur. In fact, it is rather common for scientific theories to remain suspended for years between proof and disproof*.

I believe that one reason that some have claimed that the theory is already proved false is the reliance on demonstrably false statements (about anatomy or physics), and I've tried to point those out, as IMHO they would present the most serious blocks to understanding. And to the extent that I have done that, I trust I have contributed.

I have also made less helpful comments. I will continue, instead, in the spirit JohnKSa suggests.

*In theory, an idea can never be "proved true," only proved false. However, some theories (evolution is a good example) are so firmly established by evidence that there is no practical possibility they will ever be disproven, although the theory may need its details modified from time to time.

MachIVshooter · Sep 18, 2011

I would like to publicly apologize to MachIVshooter for treating him less than respectfully on this thread.

Thank you, John.

. In the USA there are two problems, one is the imperial system in use

What's wrong with imperial? All the same measurements exist, just denoted differently. if you prefer Nm and Kw to Lb.Ft. and Bhp, that's your perogative, but it doesn't mean there's anything wrong with the latter.

In my field, I use both pretty much daily and can convert most units back and forth easily. That said, SAE units have their advantages, too. *F being finer divisions than *C, for example. More precision with integers.

I think what we're most comfortable with is what we grew up on, but that doesn't make another system inferior

brickeyee · Sep 18, 2011

Clearly he has a strong interest in this topic and equally obviously he's willing to spend time and effort learning about the physics and mathematics involved, all of which is commendable.

Maybe when he learns to use the correct units he might be worth listening to.

Pasteur · Sep 19, 2011

there is a great deal of distance between finding small vascular hemorrhages in the brains of some deer shot with high velocity rifle bullets in an uncontrolled field experiment and proving that a service caliber handgun can cause neurological incapacitation of a human with remote BPW.

Yes, of course, but this is one paper among many. Seldom does a single paper address all facets of a complex topic. The fact is that remote brain injury (from shots to the chest) was predicted before it was observed based on incapacitation and related data. Other papers provide evidence that:

1) Humans shot in the chest with handguns experience cerebrovascular damage.
2) Other factors being equal, deer shot in the chest with handgun bullets with higher ballistic pressure waves are incapacitated more quickly, on average, than deer shot in the chest with handgun bullets with smaller ballistic pressure waves.
3) Pigs shot in the thigh with projectiles transferring pistol levels of energy display depressed EEG readings that would probably correspond with incapacitation if they were not anesthetized.
4) Pigs shot in the thigh with projectiles transferring pistol levels of energy display transfer of pressure from the bullet impact to the brain (measured with pressure transducers) and neurological injury in both peripheral nerves and the central nervous system.
5) Dogs shot in the thigh with pistol levels of energy experience traumatic brain injuries. Greater energy transfer correlated with greater remote brain injury.
6) Pigs shot in the chest with rifle bullets stopped by body armor (no penetration) experience immediately depressed EEG readings that would probably correspond to incapacitation if they were not anesthetized. Pistol levels of energy are transferred to tissues behind the armor, and the degree of EEG suppression corresponds with the amount of energy transferred to thoracic tissues behind the armor.
7) Epidemiological data shows the probability of rapid incapacitation in humans is highly correlated with peak ballistic pressure wave magnitude.
8) The average incapacitation time in goats is highly correlated with peak ballistic pressure wave magnitude from pistol bullets.
9) Experiments have shown immediate incapacitation in 10 lb mammals exposed to ballistic pressure waves generated by handgun bullets without any penetration.
10) Blast pressure waves can be transmitted to the brain via the thorax resulting in brain injury.
11) Fish can be killed by bullets passing near them in the water without hitting them.
12) Studies in goats show projectile impacts to the thigh generating similar lethal outcomes to explosives taped to the thigh.
13) Brain haemorrhages have been observed in cape buffalo shot in the chest and correlated to immediate incapacitation.

As the recent paper in Neurosurgery pointed out, the totality of the evidence is compelling and hydrostatic shock is “now well established in a broad body of scientific literature.”

I should also mention that I do not believe the BPW mechanism suggests the center of mass as the proper point of aim. On the contrary, I believe the implication is that the center of the chest is the optimum point of aim, if available.

MachIVshooter · Sep 19, 2011

The fact is that remote brain injury (from shots to the chest) was predicted before it was observed based on incapacitation and related data.

I submit that one can find evidence to support almost any theory. It's been demonstrated many times. The problem is, when there is a pet theory, it seems that evidence to the contrary is often dicarded. This is human nature; We want to believe something is true, we try to prove it to ourselves and everyone else.

I am not saying this theory is entirely false, but there seems to be much more evidence discrediting than supporting. For example, for each of these animals shot in studies that have "shown immediate incapacitation from remote neurological damage" or however it is that you care to put it, there are countless hunters who have placed a high powered rifle bullet right in the boiler room and watched the animal take off like a shot (pun intended) and run some distance. I'm among that group.

Since you have cited these studies, it is incumbent on you to provide links to them if we are to believe your claims. Until then, I'm going with:

1) Humans shot in the chest with handguns experience cerebrovascular damage.

This statement is probably the worst, since it states an absolute; A single case to the contrary makes this claim false.

2) Other factors being equal, deer shot in the chest with handgun bullets with higher ballistic pressure waves are incapacitated more quickly, on average, than deer shot in the chest with handgun bullets with smaller ballistic pressure waves.

How did the test mitigate the fact that the higher energy projectiles tend to make a larger bullet penetrate deeper, resulting in greater tissue damage thus more rapid incapacitation?

3) Pigs shot in the thigh with projectiles transferring pistol levels of energy display depressed EEG readings that would probably correspond with incapacitation if they were not anesthetized.

"Probably". I love that one, because it pretty much removes any burden of proof. Nonetheless, I'd like to review this test in it's entirety.

4) Pigs shot in the thigh with projectiles transferring pistol levels of energy display transfer of pressure from the bullet impact to the brain (measured with pressure transducers) and neurological injury in both peripheral nerves and the central nervous system.

"transferring pistol levels of energy" leaves a lot of room for skewing. There are many handguns that produce much more energy than small bore rifles. That does not mean the terminal ballistics are the same. I demonstrated exactly that earlier in the thread with 10mm vs. .17 Rem.

5) Dogs shot in the thigh with pistol levels of energy experience traumatic brain injuries. Greater energy transfer correlated with greater remote brain injury.

Once again, I would like to see the test.

6) Pigs shot in the chest with rifle bullets stopped by body armor (no penetration) experience immediately depressed EEG readings that would probably correspond to incapacitation if they were not anesthetized. Pistol levels of energy are transferred to tissues behind the armor, and the degree of EEG suppression corresponds with the amount of energy transferred to thoracic tissues behind the armor.

There's that probably thing again.

7) Epidemiological data shows the probability of rapid incapacitation in humans is highly correlated with peak ballistic pressure wave magnitude.

And peak ballistic pressure wave, I suspect, is highly correlated with smaller bullets expanding less and/or having relatively shallow penetration, and larger bullets being expanded wider and driven deeper with that greater energy.

8) The average incapacitation time in goats is highly correlated with peak ballistic pressure wave magnitude from pistol bullets.

See above.

9) Experiments have shown immediate incapacitation in 10 lb mammals exposed to ballistic pressure waves generated by handgun bullets without any penetration.

Not surprised. That'd be like a human taking a cannonball.

10) Blast pressure waves can be transmitted to the brain via the thorax resulting in brain injury.

How was the blast pressure wave isolated to the thorax? Seems that would be virtually impossible to do.

11) Fish can be killed by bullets passing near them in the water without hitting them.

Probably. But then again, I've shot at fish before with .22 LR, 9x19mm and ..223, and none of the ones that weren't hit came floating up.

12) Studies in goats show projectile impacts to the thigh generating similar lethal outcomes to explosives taped to the thigh.

As is covered countless times in this forum, lethal and incapacitating have much separation. Many lethal injuries are not immediately incapacitation ones.

13) Brain haemorrhages have been observed in cape buffalo shot in the chest and correlated to immediate incapacitation.

I'd really like to see that one, since cape buffalo are well known for charging after being shot.

I should also mention that I do not believe the BPW mechanism suggests the center of mass as the proper point of aim. On the contrary, I believe the implication is that the center of the chest is the optimum point of aim, if available.

Funny, since COM targets tend to put the highest value in pretty much the same place:

Perhaps not as high as you're thinking, but definitely higher than the middle of the torso.

winfried · Sep 19, 2011

Without trying to be difficult, can you explain how a slug foot is derived, so far no one could explain this to me.

Thank you

Winfried

winfried · Sep 19, 2011

Hi John, yes this is the book. I have a copy with my nickname embossed on the cover. Only for serious study.

Regards

winfried · Sep 19, 2011

You can shoot somebody in the chest, hit the lungs, in which no, and I repeat absolutely no pain is felt. I have quite some cases on record of this and I have cases where an abdominal shot is instantly disabling.
Furthermore, at handgun velocities, 50 to 80ms are needed (or lost) to penetrate skin. Then comes very soft ribcage, if bullet has not expanded when passing the ribs, no bullet expansion takes place in the lungs, that I can absolutely swear by.
Placing a shot in the abdomen has an instantly paralyzing effect like getting a proper kick to the testicles. If anybody tells me he can still function with a full proper kick in the testicle, he either lies, has never been kicked or he is abnormal.
In one case, one of two friends was shot in the abdomen with .38Spc.RN, the other was shot through the chest whereby the heart was nicked. The one withe the gut shot collapsed and was unable to do anything.The one with the chest shot made the one with the gut shot comfortable, made a statement, after about an hour, he had to sit down and died shortly afterwards.
For the record, the one with the gut shot had a miserable life for a long time, drains from the side hanging out, lots of anti-biotic, but he made it.

Regards

MachIVshooter · Sep 19, 2011

Without trying to be difficult, can you explain how a slug foot is derived, so far no one could explain this to me.

The pound force is the force required to accelerate 1 lb at 32.174049 FPS per second (or 32.174049 lbs @ 1 FPS per seond), defined by normal earth gravity (same as Nm).

The slug is just a 32.174049 (32.2) pound weight.

http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/slug.html

Odd Job · Sep 19, 2011

Placing a shot in the abdomen has an instantly paralyzing effect like getting a proper kick to the testicles.

You may have anecdotes that indicate this, but there are other anecdotes that indicate this is certainly not always the case.
In 2004 as I was leaving work at a London Hospital, there was a drive-by shooting right outside the Accident and Emergency department. I was on the upper parking deck and I heard the shots and saw the gunman getting away on a motorcycle (riding pillion).

Two people were hit. One was an unintended target, a young woman who sustained a perforating gunshot wound to the lower leg. The intended target was an adult male who took a shot through the abdomen, involving the liver.
Both individuals ran immediately for cover into the hospital where they were routed directly to the resus bay. I guess if you are going to get shot, it's best to let it happen outside the A&E.
The guy with the liver injury was first managed by attempted interventional radiology to coil a liver bleeder. There were other complications and the patient ended up having a laparotomy.
Both of these victims survived.
I checked the male's clothing and he had a perforated jacket sleeve also. Three or four shots were fired and 9mm cases were left on the road (I stopped a bus from running over one of them).
If I had come out of the entrance just ten seconds earlier, I would have seen the shooting directly.

Vern Humphrey · Sep 19, 2011

Quote:
Placing a shot in the abdomen has an instantly paralyzing effect like getting a proper kick to the testicles.

You may have anecdotes that indicate this, but there are other anecdotes that indicate this is certainly not always the case.

I have seen men shot about anywhere you can imagine (albeit with FMJ, not expanding projectiles.) Abdominal wounds, while they can be quite serious, depending on what organs are involved, will usually not stop a man.

I have also seen game animals -- such as white tail deer -- that were gut-shot, and have tracked at least one for more than a mile.

So I would say it is rarely the case that an abdominal would will have an instantly paralyzing effect -- and when it does, I suspect it is more a psychological effect than a physiological one.

brickeyee · Sep 20, 2011

Without trying to be difficult, can you explain how a slug foot is derived, so far no one could explain this to me.

Thank you

Winfried

It is as simple as the difference between mass and weight.

English vernacular does not deal with mass, it deal with weight.

To have a consistent set of units for scientific work we need a unit of mass.

By dividing weight (a force) by the acceleration that created it (gravity) we have a unit of mass (F=ma, so m=F/a).
This unit is (somewhat facetiously) called a slug.

Now the regular expressions for energy (like 1/2 * m * v^2) work consistently,.

The metric system as commonly used has the same problem.

No one states their weight in Newtons (the unit of force) but uses kilograms (the unit of mass).

Your weight depends on gravity (acceleration), your mass is constant.

If your weight is 200 pounds on earth, your mass is ~6.2 slugs.

Your weight on the moon would be about 33 pounds, but your mass would still be ~6.2 slugs.

JohnKSa · Sep 21, 2011

I am not saying this theory is entirely false, but there seems to be much more evidence discrediting than supporting. For example, for each of these animals shot in studies that have "shown immediate incapacitation from remote neurological damage" or however it is that you care to put it, there are countless hunters who have placed a high powered rifle bullet right in the boiler room and watched the animal take off like a shot (pun intended) and run some distance. I'm among that group.

The example you give and others like it won't discredit the theory because there is no claim made that BPW is ALWAYS an incapacitating effect, even when using a round that generates a relatively high BPW.

The material is fairly clear that you can increase the chances of BPW being an incapacitating factor but that's about it. No one is selling BPW as a 100% reliable mechanism for incapacitation. Which means that finding a situation where BPW didn't incapacitate doesn't cast any doubt on the theory at all.

"Probably". I love that one, because it pretty much removes any burden of proof.

Regardless of whether the "probably" is true or not, the EEG does show effects. That's a result, in and of itself that provides evidence of remote neurological effects due to bullet strikes.

"transferring pistol levels of energy" leaves a lot of room for skewing.

You have to understand the context. The claim has been widely made that remote effects are a non-issue in handgun incapacitation. Therefore, showing that remote effect ARE an issue at "pistol levels of energy" is a significant result. While your point is accurate, the claim being addressed by the assertion is so sweeping that a carefully qualified energy level is not necessary to demonstrate that a contradiction exists.

Not surprised. That'd be like a human taking a cannonball.

The key phrase in the claim was "without penetration". The bullet did not touch the test subject. In other words, any effects due to actual penetration of the bullet were excluded from having an effect on the test subject. And yet some of the test subjects were incapacitated and showed evidence of neurological trauma/damage.

At this point, I believe that there is enough evidence from enough different sources demonstrating remote effects of BPW that it is essentially impossible to deny that BPW can cause remote effects leading to incapacitation in some cases. Further, based on the evidence I've seen from numerous sources, it is not possible to effectively support an assertion that BPW can be completely excluded as a significant effect even if we limit things to handgun incapacitation. In other words, the theoretical part of the battle has been won by the BPW researchers. They have enough evidence to prove it exists and that it can be a factor even at handgun energy levels.

Which means that the focus of the BPW debate will now swing toward how much of a practical effect it has, how probable that effect is, and what can be done from a practical perspective to offer the best chance to bring it into play in the real world. That may actually be a much tougher nut to crack.

MachIVshooter · Sep 21, 2011

The example you give and others like it won't discredit the theory because there is no claim made that BPW is ALWAYS an incapacitating effect, even when using a round that generates a relatively high BPW.

The material is fairly clear that you can increase the chances of BPW being an incapacitating factor but that's about it. No one is selling BPW as a 100% reliable mechanism for incapacitation. Which means that finding a situation where BPW didn't incapacitate doesn't cast any doubt on the theory at all.

It does seem that it is the goal of some, though, with statements like

Originally posted by Pastuer said:
1) Humans shot in the chest with handguns experience cerebrovascular damage.

No, the term "incapacitation" doesn't appear here, but seems implied. And, as I said earlier, stated as an absolute, this claim is easily made false by just one example of it not occuring.

Regardless of whether the "probably" is true or not, the EEG does show effects. That's a result, in and of itself that provides evidence of remote neurological effects due to bullet strikes.

It does show evidence of remote effects, and as I've been saying all along, I don't think any of us are questioning that there can be effects, but rather the magnitude. Kinda like seismic activity; It has to get to a certain level to be felt, and far more to cause damage.

showing that remote effect ARE an issue at "pistol levels of energy" is a significant result.

I guess if we're hung up on the notion that energy is the only factor. But I don't think anyone can argue that velocity is not a significant factor in wounding ability. As well, "Pistol levels of energy" has quite a bit of ambiguity these days, with certain handgun rounds making more energy than a .308. This thread seems to center largely on whether these effects are present with service caliber handguns, and that is not defined here.

The key phrase in the claim was "without penetration". The bullet did not touch the test subject. In other words, any effects due to actual penetration of the bullet were excluded from having an effect on the test subject. And yet some of the test subjects were incapacitated and showed evidence of neurological trauma/damage.

I know, and I understood that. I've caught the bits Courtney has mentioned about chest wall acceleration, etc. from explosive shockwaves, too. My point was that this test used a 10 pound animal. It's about scale, so even assuming a service caliber round like .45 ACP ball ammo, if scaled up to man size (like the 70 Kilo weight stipulated in the army tests you linked, which 154 Lbs. is small by current standards), you're talking about a half pound projectile developing 6,000 ft/lbs. I'm sure that would cause considerable damage, even if stopped by a vest.

A service caliber bullet that can kill a man will absolutely destroy a rabbit sized animal, but have virtually no effect at all on something the size of an elephant. That is my point.

At this point, I believe that there is enough evidence from enough different sources demonstrating remote effects of BPW that it is essentially impossible to deny that BPW can cause remote effects leading to incapacitation in some cases.

I agree.

That said, I still would like to know more about how the BPW effect was isolated from everything else. Were they able to somehow demonstrate that the local injury absolutely could not have incapacitated that quickly through blood loss/damaged vital organs? And, if so, how do we isolate the neurological effects of the BPW from the psychological effects of major trauma?

It is just my nature to always be skeptical, always question. Sometimes it may come across as hostile or accusatory, and for that I am sorry. But there are still many questions to be answered, specifically correlation vs. causation. Things like the EEG results are a step in the right direction here, but IMO, are a long way from concluding that there would have been incapacitiation resulting from BPW-caused remote neurological damage.

KenB22 · Sep 21, 2011

We can argue about this for days. What do the people in the industry or who put their lives on the line every day think of this theory? My research suggests the IWBA, FBI etc have no use for this theory. If they don't use it as a factor in their choice of ammo, why should we?

JohnKSa · Sep 22, 2011

No, the term "incapacitation" doesn't appear here, but seems implied. And, as I said earlier, stated as an absolute, this claim is easily made false by just one example of it not occuring.

It is if he meant to say "All humans shot in the chest...". Based on the contents of his papers and his other comments, I don't believe that would be an accurate restatement of the sentence.

I guess if we're hung up on the notion that energy is the only factor.

Energy provides a convenient method for calculating force and therefore pressure using easily measured data (penetration). One could do the same calculations with momentum, but then one would need to know the deceleration time which would be harder to measure. So it's not that energy is the only factor, it just happens to be convenient because of the information available.

But I don't think anyone can argue that velocity is not a significant factor in wounding ability.

It's not possible to separate velocity from kinetic energy, or from momentum. It would be accurate to call them 3 sides of the coin--if there were such a thing as a 3-sided coin, that is.

You can calculate the applied force using either kinetic energy and penetration, or from momentum and deceleration time, or, directly from velocity, penetration distance and deceleration time using the F=ma equation. The results are the same regardless of which route you choose to take. It's just that in this case it's easy to measure penetration and energy while measuring the deceleration time would be much more complicated.

This thread seems to center largely on whether these effects are present with service caliber handguns, and that is not defined here.

At least one of the papers linked on this thread contains a more careful quantification of the energy levels and the range does contain at least some of the service pistol calibers.

That said, I still would like to know more about how the BPW effect was isolated from everything else. Were they able to somehow demonstrate that the local injury absolutely could not have incapacitated that quickly through blood loss/damaged vital organs?

Yes, the tests done that coupled the BPW to the test subject via water and didn't involve any penetrating injury to the test subject isolate the BPW from everything else by eliminating all factors related to penetration injuries.

http://www.ballisticstestinggroup.org/lotor.pdf

The test subject's heads were out of the water so the only method for inducing any incapacitative effects to the brain were by coupling the BPW through the water, into the body and then through the blood vessels to the brain.

The comments about the issues of scale are to the point, however, the test results are still very revealing because they do eliminate the confusion about whether the incapacitation was due to penetrating injury and also because the results (probability of incapacitation) tracked the calculated BPW figures very well. In other words, the tests weren't to claim that a particular loading that produced 3 out of 5 incapacitation results on the test subjects will also produce similar results in humans. The point was that the effect can exist in the absence of a penetrating wound and that the observed effect does correlate well with predicted BPW.

It is just my nature to always be skeptical, always question.

A reasonable approach, nothing wrong with that.

If they don't use it as a factor in their choice of ammo, why should we?

Since you asked, here's my take.

I wouldn't consider trading a very predictable performance parameter, like penetration, for a probabilistic factor like BPW. BUT, if one were making a choice between two loadings that both meet all the criteria for penetration, shootability, etc. then one might as well choose the one that is predicted to provide the strongest BPW. It can't be any worse than flipping a coin.

Loosedhorse · Sep 22, 2011

Since you asked, here's my take.

And here's mine: I'm not sure I need as much penetration as the FBI does.

The FBI went to its current recs after the Miami Shoot-out, specifically after one agent's 115 gr Silvertip 9mm (c. 1200 fps) fired from perhaps 10 yards penetrated an arm, a chest, collapsed a lung, severed a vital artery...but stopped an inch short of the heart. It is presumed that if the heart, rather than the artery, had been hit, all would have been different.

In moving to the 10 (temporarily), the FBI said of the 9:

We are saying it is as good as a .38 Special, which has served us for a long time. It has severe limitations, which we are not willing to accept. It is woefully inadequate for shooting at people in cars, for example, and over half of our shootings involve vehicles. It is a marginally adequate wounding agent.

So, one reason for the emphasis penetration is that over half of their shootings involve vehicles.

Also: one of the enduring mysteries of Marshall and Sanow's "Stopping Power" data was the .32 ACP "old" Silvertip: 63% one-shot stops (same as .45 hardball) and 6.5 inch penetration? How's that possible?

Of course, one possible explanation is bad data. But unlike most of the calibers they looked at, the .32 ACP (even then) was not favored by uniformed police, so that the shootings for this round were weighted toward private citizens and undercover cops, who were thought not to be armed. How would these shootings be different (on average, not always) from uniformed police shootings?

Less dedicated attacker: didn't expect his victim was armed, more likely to stop or run if hit once
Closer range with fewer obstacles
More likely to have a frontal chest target
Others?

Even I am not happy with 6.5 inches of penetration (or 63%), but I'm not sure I should sneeze at 9.5. Nothing wrong with the FBIs minimums; I just remember that they were developed for the FBI with particular attention to THEIR typical shootings, and therefore their particular balance between under- and over-penetration.

And if I can get 9.5 or 10" of penetration plus a BIG (say, 700 ft-lb) energy dump; or 14" and a small one; well, I know which the FBI would choose. But I might choose differently. JMHO, YMMV.

2zulu1 · Sep 22, 2011

It appears Dr Courtney is posting under the psuedonym of Pasteur.

In Courtney’s own words;

Scientific Evidence for “Hydrostatic Shock”

“Hydrostatic shock” expresses the idea that organs can be damaged by the pressure wave independently from direct contact with the penetrating projectile. If one interprets the "shock" in "hydrostatic shock" to refer to physiological effects rather than physical wave characteristics, the question of whether the pressure waves satisfy the definition of “shock wave” is unimportant. There is compelling scientific evidence supporting the ability of a ballistic pressure wave to create tissue damage and incapacitation in living targets.

Energy Transfer Required for Remote Neural Effects

Our own research (Courtney and Courtney) supports the conclusion that handgun levels of energy transfer can produce pressure waves leading to incapacitation and injury.[29][30][26][31][32] The work of Suneson et al. also suggests that remote neural effects can occur with levels of energy transfer possible with handguns (roughly 500 ft-lbs/ 700 joules).

Recommendations

The FBI recommends that loads intended for self-defense and law enforcement applications meet a minimum penetration requirement of 12” in ballistic gelatin.[8] Maximizing ballistic pressure wave effects requires transferring maximum energy in a penetration distance that meets this requirement. In addition, bullets that fragment and meet minimum penetration requirements generate higher pressure waves than bullets which do not fragment. Understanding the potential benefits of remote ballistic pressure wave effects leads us to favor loads with at least 500 ft-lbs of energy.

However, Duncan MacPherson discounts the enregy transfer statement by Courtney.

“. . . every now and then someone wants to analyze or think about a problem involving energy, and when they attempt to do this without really understanding energy or other thermodynamic concepts the result is unfortunate. One such problem is the analysis of any of the various aspects of terminal ballistics; some individuals with inadequate technical training and experience have unwisely and unproductively attempted to use energy concepts in the analysis of bullet impact and penetration in soft tissue. (Many others have simply assumed that energy is the dominant effect in Wound Trauma Incapacitation; this assumption is even more simplistic than the attempt to actually analyze the dynamics problem with energy relationships, and is no more successful).

Any attempt to derive the effect of bullet impact in tissue using energy relationships is ill advised and wrong because the problem cannot be analyzed that way and only someone without the requisite technical background would try. Many individuals who have not had technical training have nonetheless heard of Newton’s laws of motion, but most of them aren’t really familiar with these laws and would be surprised to learn Newton’s laws describe forces and momentum transfer, not energy relationships. The dynamic variable that is conserved in collisions is momentum; kinetic energy is not only not conserved in real collisions, but is transferred into thermal energy in a way that usually cannot be practically modeled. The energy in collisions can be traced, but usually only by solving the dynamics by other means and then determining the energy flow.

From Dr Gary Roberts;

"...I was a member of the Joint Service Wound Ballistic Integrated Product Team, the U.S. government study that gathered numerous experts from a variety of disciplines, including military and law enforcement end-users, trauma surgeons, aero ballisticians, weapon and munitions engineers, and other scientific specialists to conduct a 4 year, 6 million dollar study to determine what terminal performance assessment best reflected the actual findings noted in OCONUS combat the past few years. Courtney's "hydrostatic shock" was NOT found to be a valid or relevant factor. Likewise, I work at a large Level I trauma center and get to treat people who are shot in the face and jaws--guess what, NO remote CNS or other "hydrostatic shock" effects of the type Courtney espouses have occurred in ANY of these patients.

"...JSWB-IPT was initiated in 2002 and concluded in 2006. I should note that the joint USMC-FBI ammunition study of 2006 also found the same results. Oh...and the CTTSO/TSWG MURG program of 2007-2008 also made the same conclusions. Please think through this--the JSWB-IPT, FBI BRF, AFTE, and other organizations get to assess an extensive amount of post-shooting forensic data; the whole raison d'être of these independent, non-profit organizations is to interpret and disseminate information that will help LE and military personnel more safely and effectively perform their duties and missions. Why would they discount or ignore a potentially important incapacitation mechanism if there was any validity to it? I challenge you to read through all of the papers cited in Courtney's work and then make you own conclusions--everyone I know who has done just that has walked away utterly unconvinced of their merit."

Currently I am qualified on .45 ACP 1911 and 9 mm Glock; if I ever go back to LE Patrol duties, I'll likely carry a .40 S&W M&P. I don't really care that much about which one I am issued, as ALL the handgun service calibers work similarly.

During the early to mid 1980’s, like many people, I was duped by articles singing the praises of the .357 Mag 125 gr JHP. I carried a 4” 686 and a customized 3” M13 loaded with Fed 125 gr JHP. However, after going on active military duty and being in a position to test ammunition at the Letterman Army Institute of Research with Dr. Fackler, it became obvious that the .357 Magnum 125 gr JHP’s tended to have relatively shallow penetration, frequently fragmented with resultant decrease in permanent crush cavity, and had temporary cavities of insufficient size to contribute significantly to wounding. In addition, these loads had a large muzzle flash and blast, as well as a relatively harsh recoil which inhibited accuracy and re-engagement speed. As the FBI established a science based ammunition testing program, their research data also showed less than stellar performance from the lightweight .357 Mag loadings, including the 125 gr JHP’s. For those individuals who doubt evidence based research and prefer “street results”, the CHP, the largest agency to issue .357 Mag 125 gr JHP’s on the West Coast, clearly reports significantly better results in their officer involved shootings since switching to .40 S&W 180 gr JHP loadings, based on officer perception, objective crime scene measurements, as well as the physiological damage described in the relevant autopsy studies. The CHP used a variety of .357 Mag loads, depending upon what was available via the state contract. According to the published CHP test data from 1989-90, the .357 Magnum load used immediately prior to the CHP transition to .40 S&W was the Remington 125 gr JHP with an ave. MV of 1450 f/s from their duty revolvers. I first saw the data when it was presented during a wound ballistic conference I attended at the CHP Academy in the early 1990's; I heard it discussed again at a CHP Officer Involved Shootings Investigation Team meeting in November of 1997 at Vallejo, CA. The information reviewed the differences in ammunition terminal performance such as penetration depth, recovered bullet characteristics, tissue damage and other physiological measurements and physical evidence detailed during forensic analysis..."

Dr. Roberts is currently on staff at Stanford University Medical Center; this is a large teaching hospital and Level I Trauma center were he performs hospital dentistry and surgery. After completing his residency at Navy Hospital Oakland in 1989 while on active military duty, he studied at the Army Wound Ballistic Research Laboratory at the Letterman Army Institute of Research and became one of the first members of the International Wound Ballistic Association. Since then, he has been tasked with performing military, law enforcement, and privately funded independent wound ballistic testing and analysis. He remains a Navy Reserve officer and has recently served on the Joint Service Wound Ballistic IPT, as well as being a consultant to the Joint FBI-USMC munitions testing program and the TSWG MURG program. He is frequently asked to provide wound ballistic technical assistance to numerous U.S. and allied SOF units and organizations. In addition, he is a technical advisor to the Association of Firearms and Toolmark Examiners, as well as to a variety of Federal, State, and municipal law enforcement agencies. He has been a sworn Reserve Police Officer in the San Francisco Bay Area, where he now he serves in an LE training role.

Dr. Courtney (Pasteur) was not a part of the multi-million dollar research projects.

JohnKSa · Sep 23, 2011

However, Duncan MacPherson discounts the enregy transfer statement by Courtney.

Yes, he does. I wonder if he's reconsidered that stance given the proof that is now available to support many of Courtney's claims.

Dunno what to say about Dr. Roberts' comments. Clearly remote effects from hydrostatic shock are well-established fact and have been for many decades. A quick perusal of Wound Ballistics by Coates & Beyer, published in the early 1960s shows that the studies done for the book demonstrated conclusively with photographic (high-speed X-Ray) that hydrostatic shock was capable of breaking bones that weren't struck by a projectile passing through nearby tissue.

GLOOB · Sep 23, 2011

Hydrostatic shock doesn't have to kill a person to have an effect.

If you poke a person in the right spot with 3 fingers, you can near instantly incapacitate or distract him for several seconds with ZERO permanent damage. Enough time to followup with some more lasting strikes.

If a bullet causes a greater temporary wound cavity, it would obviously have some greater effect than a bullet that makes the exact same wound channel with no cavitation. It might not increase mortality, but it might cause enough temporary neural disruption to change an attacker's attitude, when placed in the right spot.

pisc1024 · Sep 23, 2011

Pasteur said:
12) Studies in goats show projectile impacts to the thigh generating similar lethal outcomes to explosives taped to the thigh.

You can't be serious about this statement. Please tell me you were just exaggerating, and that you were trying to make a point. To say that a GSW is in any way shape form or fashion is even close to high explosives going off on or near your body is in my mind stating that one has NO CLUE how explosives work. Further more that statement would suggest that you have obviously never done a study to back this up your self.
I would be very interested in these "studies" you speak of. And no, shoving fire crackers into the mouths of frogs dose not constitute a study.

I would also suggest you refrain from using any studies quoting incapacitation times of goats to possible similarities in people. Goats are a horrible comparison to people. Goats have a notoriously low will to live, that is why the U.S. Military uses them in advanced medic courses as training aids.

Kachok · Sep 23, 2011

OK let me sum up the "hydrostatic shock" theory. Yes bullets to create a shock/temporary wound cavity, yes it does inflict some level of additional damage, no it does NOT outweigh the need for penatration and crushed tissue through the vital organs of the target....not even close. NEVER EVER choose a hangun bullet for the size of it's pressure wave or shock cavity, the FBIs Handgun Wounding Factors and Effectivness handbook discribes it best. Basicly they say that reliable stopping is a result of rapid blood loss not a shockwave. According to the FBI all handgun rounds should penatrate to a MINIMUM of 12" to be effective, so forget all the hype around fragmented ammo it is just that hype nothing more. Think about it, what causes more phisical damage, an 22LR bullet passing through the heart and lungs or a 45 ACP stretching the fat and muscle tissue for the first 5"? If you have to think about that you don't know much about terminal ballistics. Energy dump theory belongs in the dump, relying on a pressure wave to casue a concussion like effect to stop a threat is simply not even close to reliable. Plowing a 3/4 inch permanate wound cavity through the vital organs is not perfect nor usualy instant, but it is the most reliable thing we can achieve at handgun speed/energy levels. A determined attacker can function for 15 seconds with complete loss of blood pressure to the brain, this is the result of residual oxygen in the brain, so if you are expecting a bang flop out of any handgun bullet you will be sorely dissapointed.

Loosedhorse · Sep 23, 2011

Duncan MacPherson said:
Many individuals who have not had technical training have nonetheless heard of Newton’s laws of motion, but most of them aren’t really familiar with these laws and would be surprised to learn Newton’s laws describe forces and momentum transfer, not energy relationships. The dynamic variable that is conserved in collisions is momentum; kinetic energy is not only not conserved in real collisions, but is transferred into thermal energy in a way that usually cannot be practically modeled.

I'm not sure what MacPherson's point here is.

The fact that Newton's Laws of Motion don't mention energy does not change the fact that Conservation of Energy is a law of physics. Energy is conserved in collisions: if a bullet hits an object and does not emerge, then all off the bullet's energy has been absorbed by (or dissipated by, or "dumped into") that object. Some of that energy is used for destroying tissue, some for creating (temporary) movement of tissue (and that movement is eventually changed to heat as the tissue again comes to rest), and some to shock wave (which also eventually becomes heat).

Fine. How does that argue for or against BPW? Why does it matter if Newton mentioned energy or not? He seems to be condescending ("... most of them aren’t really familiar..."), but for no cause, and to no purpose.

Kachok said:
Basicly they say that reliable stopping is a result of rapid blood loss...

Yes, or loss of CNS function. In other words, rapidly lethal wounds. And yet we know that the majority of those suffering handgun wounds survive.

WISQARS lists 326 law-enforcement-caused firearm deaths and 1663 non-fatal law-enforcement firearm injurys for 2008. The implication is that something other than lethal injury stops the majority of attackers. The FBI says we should ignore that; and from a "what you can plan for and predict" perspective, I see their point. But I'm not sure I ready to, as they do, simply ignore the results of most gunfights.

Kachok · Sep 23, 2011

I don't think the FBI is ignoring the fact that the vast majority of handgun shots are not leathal, they are making a case for what is effective on a detirmened threat, hydrostatic shock does not stop them, temporaory cavity does not stop them, only loss of blood pressure leading to incapacitation or death stops them reliably, aside from a CNS shot anyway. Creating rapid blood loss is best aheived by penatrating blood bearing organs or major vesles/artiers. Expanded bullets increase the chances of crushing, ripping these targets, but having enough penatration to reach these targets is the the most fundimantal aspect to lethality/incapacitation ability. Only a small handful of people have tried to depate me on this topic, and usualy those who have tried don't know enough about termianal ballistics to actualy debate, much less realize when they are just plain wrong. They just spout whatever they read on some highly bias website for whatever handgun caliber they worship.
Bullet construction has alot more to do with terminal performance then weather it is a 9mm, 40, or 45. I have seen standard pressure 9mm out perform poorly designed 45s and I have seen 45s make huge permanate wound cavities that surpass the more powerful .40 S&W.

The hydrostatic shock theory?

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