Hydrostatic Shock (pistols)

[LaserSpot]

http://www.thegunzone.com has a lot of info on that shootout too.

In the aftermath, FBI tests determined that penetration was the most critical factor, not "shock".

No one said that shock is the most critical factor, we've been debating whether it exists at all for handguns. I think it is a factor for larger handguns, but I would place its importance at #3, behind adequate penetration depth and diameter.

It's too bad the FBI abandoned the 10mm; that round had the potential to satisfy both camps: make a big deep hole, and explode.

 

[shep854]

Good call, LaserSpot; I had forgotten about TGZ.

 

[MCCALL911]

Robert A. Rinker called "Understanding Firearm Ballistics"

Yes, I have it and have read it.

Back to the topic...

OK, so I'm duly "dismissed."

Without trying to sound like some kind of internet pedant, I was trying to make a point. But I failed because I couldn't get off the ground due to misunderstandings (that I'm still scratching my head over.) Sorry to disrupt the smooth flow of the conversation.

 

[RETG]

To correct a mistake someone made, depending on the atmospheric pressure and temps, the speed of sound as measured in feet per second can be approx. 1100 feet per second. Many 9mms and smaller or even larger bullets can travel at that speed. It depends on the weight of the bullet, length of the barrel, etc. (Testing my Hornady 115 gr in my 9mm shows around 1150 fps, past the muzzle.)

So, yes, Handgun ammo can cause hydrostatic shock in a person. And it does not have to hit the head.

I do know there have been quite a few studies done on autopsied bodies that show hydrostatic shock is more than a myth, but something you cannot count on, regardless of the ammo used. Not being an expert on this, I can imagine that there are an extreme number of factors that will allow or disallow hydrostatic shock. Some of these might be not only the bullet and where it hit the human body, but the weight of the person hit, muscle vs. fat, bone structure, etc. In addition, how close the person is who is shooting in relation to the person being shot.

Again, not sure if that is true about the factors, but it sure sounds plausible. But I'll continue not to worry about it and pick my rounds on other factors

 

[Crosshair]

To correct a mistake someone made, depending on the atmospheric pressure and temps, the speed of sound as measured in feet per second can be approx. 1100 feet per second. Many 9mms and smaller or even larger bullets can travel at that speed. It depends on the weight of the bullet, length of the barrel, etc. (Testing my Hornady 115 gr in my 9mm shows around 1150 fps, past the muzzle.)

So, yes, Handgun ammo can cause hydrostatic shock in a person. And it does not have to hit the head.

Incorrect.

If humans were made of air your point would be correct as your figures are for the speed of sound IN AIR. However, humans and animals are made of mostly WATER, so one needs to check for the speed of sound in WATER/TISSUE. The speed of sound in tissue is around 4500 fps.

 

[shep854]

(NOT trying to pile on RETG, I promise)

The reason 1000fps is important to handgun bullets is that for a long time it was the minimum velocity that would ensure opening up of hollow-point bullets. Newer tech may have lowered this, but 1000fps is still the benchmark.

Regarding the speed of sound in different media, it gets faster the denser the medium.

 

[RETG]

Crosshair:Incorrect.

If humans were made of air your point would be correct as your figures are for the speed of sound IN AIR. However, humans and animals are made of mostly WATER, so one needs to check for the speed of sound in WATER/TISSUE. The speed of sound in tissue is around 4500 fps.

I guess I should have quoted the person I was correcting, but did not. It was concerning post #9 where it is state the speed of sound was 2000 fps. Now, possibly that person was stating what the speed of sound as in a human body. I took it as being in the air, and maybe I was incorrect. However, my statement is for air, not water, or any other substance.

shep854: (NOT trying to pile on RETG, I promise)

The reason 1000fps is important to handgun bullets is that for a long time it was the minimum velocity that would ensure opening up of hollow-point bullets. Newer tech may have lowered this, but 1000fps is still the benchmark.

Regarding the speed of sound in different media, it gets faster the denser the medium.

Do not worry about piling it on.

Only thing I ever heard about 1000 fps concerning hollow point ammo was this was the reason hollow point is used extensively in handguns and not in higher velocity weapons. High velocity weapons, primarily rifles do not require hollow point ammo. However, those weapons (i.e., handguns) that have muzzle velocities below approx. 1000 fps require hollow point ammo to allow for an effective round.
I have never heard that 1000 feet is the minimum required for hollow point to expand since the expansion happens at the point of impact, not while flying through the air. Possibly, the actual expansion has more to do with energy at point of impact vs. speed at point of impact.
I am NOT a ballistics expert, and I did not stay at a Holiday Inn last night, so what I am saying might be incorrect. However, over my years I have discussed these subjects on occasion, but not with great detail, with people who could be considered ballistics experts and to the best of my knowledge and memory, this is what I have learned.
If there is some definitive information on the fact that 1000 fps was the minimum for a hollow point to expand, please post it up. I am always willing to learn, even at my ripe old age. In addition, it will give me another reason not to carry a .45, since most .45’s do not have a muzzle velocity greater than 950 fps.


As for the statement on the speed of sound, again, I was referencing what I think was someone stating 2000 fps was the speed of sound in the air. I understand the speed of sound increases in denser materials (aluminum it is around 20K fps…I believe I read this once). Again, since not many bullets will be worth a darn after being shot through a slab of aluminum, I was talking about just good old air.


As for hydrostatic shock...well, some of these balistics experts I have talked with over the years, including some ME's I have had the good fortune to know, will say it is a possibility and does exist. But is extremely rare. And to be honest, and hopefully not insulting to anyone here, these guys and gals know more than anyone on this board and that includes me by a mile. So, I'll continue to believe in it, but I will NEVER bet my life that it will happen if I need go shoot someone in self-defense. I'll continue to look at normal balistics, based on other factors, to decide my self-defense ammo.

 

[shep854]

"Possibly, the actual expansion has more to do with energy at point of impact vs. speed at point of impact."--RETG

Yes, that is what I was trying to say, but didn't state clearly.

I don't remember specific cites, but was recalling articles read over the years. Given that newer bullet designs are out that are intended for lower velocities (with short-barreled guns in mind*), the 1000fps floor is becoming moot.

*Speer "Gold Dots", especially those made for .38spl, come to mind. IIRC, they were designed to expand out of snubbies.

 

[jon_in_wv]

The problem with most handgun rounds is that they don't create ENOUGH hydrostatic shock to be a reliable factor in wounding. Most tissue is pretty pliable and the handguns rounds don't create enough stretching to cause tearing of the tissue. They may cause a lot of bruising and they will damage less pliable tissue but it is not to the extent of rifle ammunition. The problem with the topic is since the FBI's report where they listed such things as hydrostatic shock as not creating RELIABLE stopping power so people assume it has no effect. The fact is if I was given the choice between two bullets with equal expansion and penetration and one of them was higher velocity I will take the one that is capable of creating more hydrostatic shock. Others will argue that since the expansion and penetration are the same then the terminal performance of the bullets is exactly the same. Case in point: One poster I debated with stated that a .308 Winchester that expanded to .60 inch and penetrated 15 inches and a .45 acp that expanded to .60 inch and penetrated 15 inches both had exactly the same terminal performance and there was no benefit to the .308. The fact is the .308 will be MUCH more effective. The difference in performance between pistol rounds will be much less dramatic however but if it gives even the slightest edge then I think its worth it in the long run.

 

[sanchezman]

Hydostatic Shock

Some people are nuts. The only way to damage the brain is to hit it with a bullet. The only weapon that would create a shock wave powerful enough to damage the brain with a shock wave would be an RPG, or an M1 tank.

Um peetzkiller I don't mean to berate on your knowledge or anything but that is not true, I'm a former marine & I know that the M16A2 can & will cuase hydrostatic shock on most occasions.

I'm pretty sure the muzzle velocity is around 2700 fps, We're trained to shoot for center mass when possible with controlled pairs, [A.K.A. hammer pair]

I'm not a grunt & I can't say that i've had first hand experience but i've been on a few patrols before & there were a coupel times when we had to breach a house & I distinctly remember three different times when some insurgents that ahd been shot [hammer pair] died within seconds, Really they went into shock almost immediately after being hit, My Sergeant used to say it was hydrostatic shock.

Althou I cannot say that the round its self will guaranteed cause hydrostatic shock, I do know a hammer pair to the chest will usually have a high chance of causing hydrostatic shock.

And also from what I was told by a navy corpsmen, HE said that hydrostatic shock doesn't cause brain damage, More or less it pretty much renders the victim unconscious [In a nutshell] then they die very quickly afterwards.

Don't take any of this stuff as a fact, It's all just things I've picked up on while I did my 4 years.
Basically, Hydrostatic shock can be caused by rifles [I highly doubt a handgun].
Also in terms of stopping power, If you suspect that you might have gangsters & crooks breaking into your house wearing flak vests then maybe you should think about getting a handgun that shoots a very high velocity round, If NOT then I would without a second thought look for a handgun thats chambers a much heavier round, i.e. 45ACP My personal favorite.

 

[nolaOE800]

i didn't feel like reading all 4 or 5 pages of this thread so I don't know if anyone has offered anything like this already, but about 4 years ago, a coworker of mine took all 15 pellets from a 00 buck to the shoulder. MAJOR reconstructive surgery, and a very long recovery time.

the point of the story is that he's still here, and his brain is still razor sharp.

I'm not saying that I've completely written off the theory of hydrostatic shock, but I don't think that it plays a pivotal role in a caliber's effectiveness.
although, you can find plenty of charts and stats that test the theory, and the results are rather interesting (assuming that the stats aren't just made up by some idiot with too much free time, i mean, this IS the internet)

 

[DasFriek]

I have noticed a few things in the handgun realm. The .357, 10mm both are constantly high rated man stoppers, Why? High velocity and hydrostatic shock imo.
Both will over penetrate a body which is bad or so were told as it doesn't dump its full potential energy into the body. If that were the case then they would be less effective and the 9mm should be better than the .357 and the .40 better than the 10mm, But thats not the case.

A .223 round is almost the same exact diameter as a .22lr and it will over penetrate every time, Most likely dumping very little energy into a body. The .22lr in most cases will dump its full energy and not exit which should in theory be more effective except in blood loss of 2 holes the .223 makes.

This is just how i look at things, And ill explain a bit more.
To overcome lack of velocity you need size and expansion which is how you control over penetration when it can cause damage to whats behind the target. This is why the .45acp is the best handgun caliber when velocity cant be achieved in high volumes.

This explains why the Sig .357 is considered more effective than a normal +p 9mm, Velocity is deciding factor.
Id like to see comparisons of the .357 sig in FMJ against a standard 9mm HP in terms of wound tract damage.

00 Buck in the shoulder doesn't produce enough hydrostatic shock, For example punch a persons shoulder with your fist from a face to face position, The shoulder will recoil backwards and not transfer enough energy into the mass of the body. This is my thoughts and i could be wrong.

Hydrostatic shock is a real thing imo.
http://www.ammunitiontogo.com/catal...oz-expanding-shotgun-ammo/cName/12-gauge-slug
In many of the "autopsies" performed on animals shot with this slug the main slug penetrated 3" but most had a very thick hide for sure. But the massive shock this slug would generate and dump with just 3" of penetration after it expanded would most likely drop most things bigger than a human instantly.
The splinters it produces will only help bleed out a little, But imo help transfer enough hydrostatic shock penetration isn't needed.

To my its like being next to a large bomb that goes off and just the shock wave alone can kill you by destroying tissue by ripping and pulling but the long term affect of it killing cells themselves.

 

[EnoughGUN]

I think it is less about if the effect actually exists then about if it has any real effect when it comes to firearm rounds and the human body. The body is mostly water, throw, fire, launch almost any projectile into water and it is going to create some sort of pressure change in the media starting at the leading edge of the projectile and radiating outward. You can throw a rock into a pool and feel the wave under water. The only real question is does it matter? Probably not. I am no ballistic expert but from what I am reading on handgun rounds any pressure change they may make does not extend with any force past the temporary wound cavity. In a high powered round yes it could be a factor and more so as you increase the speed and mass of the bullet. Will it ever be enough to blow someone's eyes out if shot in the belly? probably not. Could it cause some level of additional damage? maybe. The body is very inconsistent so even if you have a round that would produce the effect on a great enough scale to do significant damage you would have to ht the body in an area that would maximize the effect. If you hit a body in any serious area with a projectile that would cause a huge HSS you would likely have a gigantic hole in you so would it really matter if your eyes popped out? Just seems this is like debating if bullets cause lead poisoning.

 

[Nnobby45]

A .223 round is almost the same exact diameter as a .22lr and it will over penetrate every time, Most likely dumping very little energy into a body. The .22lr in most cases will dump its full energy and not exit which should in theory be more effective except in blood loss of 2 holes the .223 makes.

Some subjects aren't as complicated as some would make them out to be. High speed bullets (rifles) produce temporary cavities that stretch tissue beyond it's ability to recover. This tears vessels and produces wounds beyond the actual permanent cavity produced by the bullet. This temporary (stretch) cavity is very important where human targets are concerned. Large game animals aren't so impressed by it. What some have referred to as "hydrastatic shock" is what's responsible for violently producing the stretch cavity. In water jugs, the water seems to explode. In human tissue, the action damages vitals and tears blood vessels.

Most hunters have seen deer severely blood shot far beyond the actual hole made by the bullet. Again, the bigger the critter, the less effect of the stretch (temp.) cavity.

Some pistol bullets produce enough stretch to play a part in incapacitation, but it's very hard to measure and real easy to argue about. Don't think there's any doubt that the 125 gr. .357's velocity induced stretch cavity contributes to incapacitation. However, incapacitation isn't something that can be counted on where pistol bullets are concerned. The pistol shooter is forced to rely on the actual damage cause by the bullet.

 

[nolaOE800]

the poster directly before me made me think of this...

I think that this debate is a little off center.

I keep seeing people talking about "death" and "brain damage" and "long term effects" of hydrostatic shock. if were talking about "manstopping" here then I think that the appropriate debate should be aimed in the direction of stopping the threat, not whether or not the person will die.

if you deliver a direct hit to a vital area of an attacker with a .22LR, he may just be able to muster the strength to fire off the rest of his magazine before he drops, but make the same shot with a .40smith or .45ACP or whatever other combat caliber you prefer, and the odds of him continuing his attack get much more slim.

I understand that this probably has alot more to do with the wound cavity than it does with hydrostatic shock, but I don't think that the theory should just be tossed aside.

I would imagine that a .380 or maybe 9mm shot to the shoulder would be similar to a good punch (in terms of kinetic energy and felt impact) but a full load of 12 gauge 00buck???!!?? try a Louisville Slugger. or a crowbar.
I guess this might seem to contradict my previous post. I don't mean to contradict myself. my only point for both posts is that while the theory of hydrostatic shock may not play a major role in ensuring the incapacitation of an attacker, and there are a plethora of examples to draw from of people shrugging off large-bore loads, the hydrostatic shock theory shouldn't just be tossed aside as BS. it holds water scientifically, maybe we just haven't designed a bullet that exploits it well enough.

just a few hundred years ago we thought that the world was flat, and that it was the center of the universe.