why isnt two holes better than one?

[Archangel]

Well, here's another toot for you. I'm posting the article instead of just the link this time.

Hydrostatic Shock
From Wikipedia, the free encyclopedia.


Hydrostatic shock is a theory of terminal ballistics that wounding effects are created by a shock wave in the tissues of the target. The term is meant to be a combination of hydrostatics with the (misnomer) effect of hydrodynamic shock. It is frequently used to argue in favor of low mass, high velocity bullets, especially in American shooting sports magazines.


Contents
* 1 Background
* 2 A Failed Theory
* 3 References
* 4 See also


Background

Hydrodynamic shock refers to a pressure wave that is created when liquid is suddenly displaced, such as by a high explosive. Although it is sometimes used by scientists (e.g. (1)), the term is a misnomer because shock waves do not occur in incompressible fluids. Such pressure waves are known to cause extensive tissue damage to organisms that they pass through, and have been studied for use in meat tenderization and antibacterial applications.

Following the development of high explosives in the 19th century, it was discovered that setting off dynamite in water caused nearby fish to die en masse. Although highly efficient, dynamite fishing was found to be extremely destructive to the environment and has been widely banned, although it is still illicitly practiced in some areas.(2)

Proponents of hydrostatic shock argue that because tissue is composed largely of water, an analogous situation can occur in tissue where organs are damaged in the same manner as fish, more by the shock wave than the projectile itself.


A Failed Theory

The theory of hydrostatic shock has been conclusively disproven. The claim that tissue behaves like water is obviously false. Water is an incompressible fluid, while tissue is a compressible solid. Tissue has memory and will return to its original shape if stretched, and can dissipate energy as it stretches. What's more, even if tissue did behave like water, the speed of sound in water is approximately 1500 m/s, but no commonly used rifle bullet exceeds 1300 m/s.

Tissue does behave similarly enough to water that a sonic pressure wave can be created by a bullet impact, generating pressures in excess of 100 atmospheres. However, a device known as the lithotriptor, commonly used to break up kidney stones, produces sonic pressure waves of approximately 5 times the amplitude of those caused by bullets. Up to 2000 such pressure waves are used in a single treatment session, with no damage to soft tissues whatsoever.(3)

From a study produced by the FBI, "Handgun Wounding Factors and Effectiveness"

The reason is that most tissue in the human target is elastic in nature. Muscle, blood vessels, lung, bowels, all are capable of substantial stretching with minimal damage. Studies have shown that the outward velocity of the tissues in which the temporary cavity forms is no more than one tenth of the velocity of the projectile. This is well within the elasticity limits of tissue such as muscle, blood vessels, and lungs, Only inelastic tissue like liver, or the extremely fragile tissues of the brain, would show significant damage due to temporary cavitation.(4)

Further, one study (5) showed that projectiles which strike above the speed of sound in water do not produce any "extra" trauma which could not be explained by the increase in drag as velocity increases.


References

* Note (1): Hydrodyne Process Research, Dr. James R. Claus. University of Wisconsin Madison. URL accessed on October 24, 2005.
* Note (2): Dynamite fishing ravages Philippines' precious coral reefs. San Francisco Chronicle. URL accessed on October 24, 2005.
* Note (3): What's Wrong With the Wound Ballistics Literature and Why. Letterman Army Institute of Research, Division of Military Trauma Research. URL accessed on October 25, 2005.
* Note (4): Handgun Wounding Factors and Effectiveness. FirearmsTactical.com. URL accessed on January 17, 2006.
* Note (5): Wounding Mechanism of Projectiles Striking at More than 1.5km/sec, Martin L. Fackler, Donald F Bellamy & John A Malinowski. B & T Ammo Labs. URL accessed on October 24, 2005.

 

[Soybomb]

Can't make a hole without applying force! All weapons are tools for applying force at a distance; some happen to apply it over a greater distance than others. (As a general rule, the farther away you can be and still apply force accurately against an opponent, the safer you will be).

I do not know if it is me to whom you are referring, but I've never said what I think kills, other than to suggest it is large holes and massive damage. I'm not takin' a side pro or con hydrostatic shock, as I believe many factors affect the lethality of a gunshot wound. I'll continue to aim for the center of mass. (That would be about due West of Boston, wouldn't it?)

--Herself

As I said I'm convinced the actual measure of force applied is unimportant, as long as its enough to make the the proper hole. To me its much like hanging a picture. I don't care how much force my hammer exerts on the nail, as long as its sufficient to get the nail in as far as I wanted. Hard hammer hits don't hang pictures, the nail in the wall does. Hard bullet hits don't stop people, the bullet going somewhere important does.

 

[trueblue1776]

an average man is slightly over weight, so we'll say hes 24in deep.

Correction: a morbidly obese man is 24 inches deep, I am huge guy, deepest part of my chest may be a bit more than a foot deep.


PS, Archangel, if water is alledgedly not compressable, how come it sucks so bad when you have some in a hydraulic system? And if flesh is as compressable as you say, then how is it that humans are 80% "non-compressable liquid" and the other, im assuming is 20% solid? I'm no Bill Nye here, but ummmmmm....

My ballistic theory: gun go BANG = Bad guy go OUCH (repeat for desired effect)

 

[RyanM]

As I said I'm convinced the actual measure of force applied is unimportant, as long as its enough to make the the proper hole. To me its much like hanging a picture. I don't care how much force my hammer exerts on the nail, as long as its sufficient to get the nail in as far as I wanted. Hard hammer hits don't hang pictures, the nail in the wall does. Hard bullet hits don't stop people, the bullet going somewhere important does.

And by the same measure, multiple hits of a "lesser" caliber are usually enough to stop someone in his tracks, just like multiple taps with a hammer can get the nail in just as far as one big whack. No matter what you're using, it usually boils down to "shoot them to the ground."

 

[Riktoven]

Correction: a morbidly obese man is 24 inches deep, I am huge guy, deepest part of my chest may be a bit more than a foot deep.


PS, Archangel, if water is alledgedly not compressable, how come it sucks so bad when you have some in a hydraulic system? And if flesh is as compressable as you say, then how is it that humans are 80% "non-compressable liquid" and the other, im assuming is 20% solid? I'm no Bill Nye here, but ummmmmm....

My ballistic theory: gun go BANG = Bad guy go OUCH (repeat for desired effect)

You got one thing right, you're no Bill Nye.

I can assure you that water is not compressable. If you really want to prove it to yourself, figure out a way to get 8 fluid ounces of water into a 6 oz. cup.

If you pull it off, you just won yourself a nobel prize.

 

[clone]

trueblue1776,

point taken. im 6'2 250 pounds, fairly fit and my COM is about 14in thick. so average would be about 17 to 18in?

 

[RyanM]

According to the FBI, the average American male's chest is 9 to 10 inches deep.

 

[Meplat]

Handgun rounds simply aren't all that powerful, especially when compared to rifle cartridges.

A given there.

They simply aren't powerful enough to cause the hydrostatic factors that come into play with rifle rounds. Their temporary cavities, if present at all, aren't impressive.

That hasn't been my personal observation on the two calibers I have used on deer (an animal approximately the same size a a human being.) With both the .357 Mag and .44 Mag, I've had to trim and discard plenty of "jellied" meat from quite large areas around the path of the bullet, thus indicating that a good deal of "tissue upset" did, indeed, occur. While I don't think the
.44 is necessarily the BEST defense round, I find it hard to argue with the Evan's study of one shot stops and it's conclusions on the .357

-Exsanguination: The path of the bullet disrupts and destroys tissue, resulting in the exit of blood from the circulatory system.

As someone who has "autopsied" several deer, (yeah, I'm curious feller), I can testify that not only is there tissue damage in the bullet path, but several inches around it. AND I've seen too many opened chest cavities with organs that looked like the product of a blender that were notin the direct path of the bullet to let ballistic gelatin results skew my views of what happens when the bullet really hits the bone. I simply can't ignore the fact that SOMETHING caused all that damage to the surrounding organs (which most certainly did NOT "snap" back due to any great elastisity on their parts.) Skin, yes. Very elastic. Have seen small holes in the skin on exit wounds hiding some pretty large craters just below the surface. Muscles and organs? No. Once jellied, always jellied.

Even with a destroyed heart, the brain retains enough blood to support voluntary movement for around 15 seconds, which is an eternity in a gunfight.

Man, did you ever nail THAT one right. When you consider the rule of two (most gunfights take place at a distance of two yards, consist of two shots being fired, and is over in two seconds) 15 seconds is indeed an eternity.

 

[Meplat]

I'm no expert, so I'm not really qualified to say I agree or disagree with this. But it is a very controversial idea, particularly when it comes to pistol bullets. Wound scientists who spend a lot of time shooting gel in the lab tend not to believe in hydrostatic shock as a wounding mechanism.

I tend to base my conclusions on seeing what a bullet actually does to living tissue. I've harvested 37 deer myself - some with rifle, some with bow - most with either .357 Mag or .44 Mag handguns. I should also mention that my parents ran a small country store, and we processed deer meat for folks around my area, which often entailed me getting the rather short end of the stick as far as dressing the deer out. Ah well, it afforded me an opportunity to at least see close up what had happened anti and postmortem.

Their belief tends to be that pistol bullets kill people in the old fashioned way - by cutting and crushing tissue and by causing blood loss. Again, there are those who disagree with them, too, so I'm not saying they're right - just pointing out that the concept is not universally accepted.

I'd tend to place more credence on lab techs who based their conclusions on seeing what bullets actually did in the real world, rather than on what they did to some man made substance. As to your skepticism, I can't say that I blame you one bit. I'm not from Missouri, but I do tend to believe in the "Show me" motto. Is there a DC coroner in the house???

 

[Ryder]

The animal was quartering towards me, and he dropped straight down when hit.

I saw the same thing. Bullet grazed the skin on the neck cutting the juggler like a knife. No other damage. That deer bleed out onto a 6 inch circle in the dirt. I've also turned both lungs of a deer into soup. Quite the surprise since only one lung was hit with a frontal shot.

 

[clone]

Ryder,

i think 9 to 10in is the ideal thickness or maybe it was the average back in the 50's and 60's. id say with most people being overweight nowdays that 17 or 18in would be more likely.

 

[Riktoven]

On the upside targets that thick should move a little slower, and bleed a little faster if they have high blood pressure.

 

[U.S.SFC_RET]

I read something somewhere that FMJs are more deadly than JHPs because you will wind up empying the whole clip of FMJs into a BG because you won't realize that you are hitting him. They say the bullets will go straight through and possibly cause personnel or collaterel damage behind the target. JHPs on the other hand they say you should know, the BG should know and hopefully the bullet remains in the target. This should allow for a couple of rounds instead of the whole clip or more.

 

[Soybomb]

Ryder,

i think 9 to 10in is the ideal thickness or maybe it was the average back in the 50's and 60's. id say with most people being overweight nowdays that 17 or 18in would be more likely.

Lets say your average getting flabby guy wears a size 42 coat. Lets say your chest is about 75% as deep as it is wide, we're kind of rectangular after all (and I think i'm overestimating the ratio). Assuming we had right angles (so its off by .5-1") that'd be 12" across the front and back of the chest, and 9" down the sides. I'd say you could count on 12" being a pretty reasonable depth for the all but andre the giant. Based on the same numbers as earlier 12" of penetration would be the depth of a man with a 56" chest circumference. If the same man had an 18" depth, he would be 84" around. Even on fat guys, most of the fat is usually carried below the chest. Now the real kicker is that 12" of ballistics gel isn't 12" of people since our chest isn't of uniform density, has bone, may have forearms in front of it, etc.

I'd rather have too much than not enough, but I don't think 12" is unreasonable even with fat americans.

 

[rangerruck]

Wikipedia entries on Stopping Power and Hydrostatic Shock.

These should be required reading. Seriously.


I'll just touch on the highlights here:

Hydrostatic shock is a myth. It does not exist.

Physiological incapacitation is caused by damaging the Central Nervous System, either by damaging it directly, or by cutting off its blood supply.

Round nose or pointed FMJ bullets actually leave holes smaller than their outside diameter. FMJ causes significantly less tissue damage per inch of penetration than expanding bullets. Less tissue damage means less bleeding, which means less chance of quickly incapacitating the target if the CNS is not hit directly.


Priorities when selecting a defensive bullet are:
1) Shot placement.
You have to be able to hit where you are aiming, and you should be aiming at the vital areas most likely to cause incapacitation.

2) Adequate penetration.
12.5-14 inches penetration in ballistic gelatin by the IWBA standard, 12-18 by the FBI standard. Less is insufficient. More is acceptable, but is not optimal.

3) Largest amount of tissue damage to the required penetration depth.
A bullet that will expand to the greatest diameter possible while still penetrating to the required 12-18 inch depth causes the most tissue damage, thus the best chance for incapacitation. However, remember #1. .44 magnum gets you nothing if you flinch too bad to hit anything.

if you go to cal tech or mit or someother good hi speed physics sites, you will see some hi speed gun shot pics that woudl disagree with you.

 

[clone]

Soybomb,

i still dont think "getting flabby guy" at 12in is average. with 2/3rds of americans being overweight i would think the thickness to be more. at least the average guy i see around town looks to average more than 12in.

 

[Shifty]

from personal experience

people can be RAPIDLY incapacitated only in the following ways.

1. hit the spine or do significant damage to the brain. headshot are not always 100%. A front and center forehead shot that cleaves neatly between the upper hemispheres of the brain may not even faze an attacker initially.
2. hit a major artery, or multiple large vessels or vascular organs in a very short span of time causing an immediate drop in blood pressure and depriving the brain of sufficent oxygenated blood. the brain still has a brief oxygen reserve however, as do all tissues in the body.
3. the primary factor which results in an immediate cessation of aggressive behavior is the mental state of the assailant. the horor stories of PCP addicts taking 50-100 rounds are true, not because the drug imbues them with superhuman strength, but because it takes away all fear and makes them immune to psychological shock.

oh the stories i could tell

and hydrostatic shock is a myth. there is a hydraulic effect on living tissue from high velocity rounds (rifles) but this is not "hydrostatic shock"

your mileage may vary

 

[trueblue1776]

You got one thing right, you're no Bill Nye.

I can assure you that water is not compressable. If you really want to prove it to yourself, figure out a way to get 8 fluid ounces of water into a 6 oz. cup.

If you pull it off, you just won yourself a nobel prize.

I also can't push a bullet down a barrel at 2000fps with my hands, does that mean air isn't compressable?

Whatever fella, I don't even really care.

 

[Meplat]

I also can't push a bullet down a barrel at 2000fps with my hands, does that mean air isn't compressable?

Whatever fella, I don't even really care.

Care not now, but if you ever get a slug of water back into your A/C compressor, you will. Water don't compress. Seen several 20 horse and up compressor heads blown all to hell trying to perform that function.

 

[Firethorn]

I also can't push a bullet down a barrel at 2000fps with my hands, does that mean air isn't compressable?

Whatever fella, I don't even really care.

Maybe not, but you can do so with a simpe pump. The lack of compressability is one of the main differences between liquids and gasses.

As for the post I saw about 'water in hydrolic lines being bad', well, most hydrolic systems I've seen actually use water, maybe with some sort of treatment to prevent contamination. A few use oil, which having water contaminate it would be bad.

 

[zahc]

Water is indeed, compressible.

Water is indeed, not very compressible at all, and is often considered 'uncompressible' the way light is often considered to travel instantly, the way weight is considered=mg and the way we consider Sine[x]=x for small x.

I'm not Bill Nye but I am a physics student, now stop your bickering, you are both wrong. The extent that water's compression is a factor in wound ballistics is pretty pointless to debate. Why not focus on more important (and proven) aspects like the fact that .45 will always be better than 9mm

 

[benEzra]

A Failed Theory

The theory of hydrostatic shock has been conclusively disproven.

Now THERE is one side of an argument masquerading as an unassailable conclusion.

The idea that pressure wave effects are nonexistent or negligible for handgun bullets is a contention, which may be true, but is certainly not established fact.

It is a vigorously debated topic, and IMHO the evidence leans toward the pressure wave hypothesis rather than against it.

 

[Archangel]

IMHO the evidence leans toward the pressure wave hypothesis rather than against it.

Can you cite some of that evidence?

 

[Archangel]

if you go to cal tech or mit or someother good hi speed physics sites, you will see some hi speed gun shot pics that woudl disagree with you.

What parts of what I posted would they disagree with? And could you post links?

 

[Meplat]

if you go to cal tech or mit or someother good hi speed physics sites, you will see some hi speed gun shot pics that woudl disagree with you.

Someone correct me if I'm wrong (and I'm quite certain someone WILL if I'm wrong ), but doesn't Wikipedia rely on internet users to supply them with all of their "expert" information?

IOW, anyone claiming to know anything about any subject can post it to them in order to expand their "knowledge base"?

I just checked, and any article can be changed by anyone with a web browser. Required reading? I don't THINK so.