Hi!
I have heard about the "shockeffect" and "hydrochock" made by the temorary cavitation of the bullet when it is inside the animal.
And I have heard that the temporary cavitation the "temporary hole around the bullet" start when the bullet velocity is over 2650FPS inside the animal!???
So bullets with velocity under the 2650FPS will not make any temporary cavitation in the animal??
And can not make the shock effect?
Is there any bullet velocity limit for the temporary cavitation?
//OK

Oh, no, there's a temporary cavity at lower velocities, too. "Hydrostatic shock" is not a physics term, it's a marketing term. If a physicist had invented it, it'd be called "hydrodynamic shock".

There seems to be more shock to the CNS (Central Nervous System), however erratically, with faster projectiles. Maybe simply because there is more energy on target.

If you haven't already, mosey on over to Harald's "wounding theories" site, and get your fill of this stuff, shooting holes in..... HTH, Dutch.

great site Dutch ty for sharing

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Alf,

Whereas a Tsunami wave could boule one over and even drown a person, some pundits believe that a high velocity bullet is so important in stretching a wound that they will actually build a marketing campaign around it, and dish it up as a newly found virtue of how one should actually kill more effectively.

The one thing we know is that a high-velocity bullet will not boule a buck over nor drown it. The military people have also come to realise that a high-velocity .223 bullet is not more devastaing than a much slower .308 bullet. Mr Kalasnikov had to fight his government not to go the .223 route, but to no avail. So many years later, and so much water under the bridge, and now we see the emergence of the 6.8 mm SPC.

I guess sooner or later sanity will dawn upon ignorance, if one bumps his head enough times against a granite rock.

Chris

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A good friend is a forensic pathologist. He has done 300 autopsies on murder victims a year for the last fifteen years.

His answer about the shock wave as a killing agent is a definite "It depends." It depends on the size and design of the projectile, the velocity of the projectile and what specific tissues it passes through. You also have to consider what time frame from impact to death you are willing to consider as acceptable.

I will use the general term "shockwave". The same shock wave will have much less effect passing through the abdomen, which is freely distensible, than it would passing through the brain, which is enclosed by the skull, which is not distensible at all.

In the end you have to shut off the electricity, either by direct effects on the CNS, or indirectly by interupting the oxygen supply to the CNS.

Ten years ago we were going to do a book on this subject to make it accessible to detectives, coroners, the military and shooters. I lost my health, and he decided that he wanted to concentrate on fishing, hunting and going on vacations with his younger and very attractive wife.

LD

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Alf, I think you are absolutely correct in some respects. However, just because you are right doesn't mean the animal will die consistently!

First off, temporary cavitation is caused by the projectile pushing (really, really, really, REALLY fast) tissue out of the way of the bullet. The tissue, in turn, pushes on other tissue, moving it out of the way, as it now has kinetic energy to do this work with. That is what causes the temporary cavity.

With respect to the "shock wave" or "hydrostatic shock", my observations concur with the science that a faster bullet creates far more shock. Whether that shock has any effect on the animal depends on where the shock originates. If the CNS system is withing range of the impact, the animal will be stunned, and hopefully, it will die from the wound before it recovers from the stunning of it's CNS.

Therein lies the crux, IMO. You can stun an animal, but you still have to create a killing wound. Shocking the CNS is not a reliable way of killing, though I find it a nice bonus. JMO, Dutch.

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"With respect to the "shock wave" or "hydrostatic shock", my observations concur with the science that a faster bullet creates far more shock. Whether that shock has any effect on the animal depends on where the shock originates. If the CNS system is withing range of the impact, the animal will be stunned, and hopefully, it will die from the wound before it recovers from the stunning of it's CNS.

Therein lies the crux, IMO. You can stun an animal, but you still have to create a killing wound. Shocking the CNS is not a reliable way of killing, though I find it a nice bonus. JMO, Dutch."

So the temporary cavitation "
hydrostatic shock" is only effective if it hit the cns?
The shock effect does not do any "killing effect" in the lungs/blodvessels?? right?
//OK

Well, no, that's not quite right, either.

Temporary cavitation is simply the maximum diameter of the wound, typically while the bullet is still in the animal, passing through. After the temporary expansion, the elasticity of the tissue causes it to "shrink" back, leaving only the permanent cavity (wound).

Hydrodynamic shock is simply poorly understood, and I've seen different authors explain the same observed effect (stunned animals) through different causal mechanisms.

One is that the impact creates a schockwave through the general tissue, disrupting the CNS.

Another is that when the bullet impacts during the contraction cycle of the heart, the impact is transmitted through the vascular system (which, presumably is expanded due to the high blood pressure, and therefore cannot absorb the additional expansion) to the CNS, causing collapse.

Personally, I don't believe the phenomenon is well enough understood to say we know what happens.

It's kind of like the "Secondary Explosion Effect". We know rifles sometimes go "kaboom" with light loads, and we have some theories, but we don't really know the why and what fore.

Alf, I noticed that you did not mention dead animals, but since the query specifically deals with those, I wanted to keep that in the discussion. FWIW, Dutch.

Alf,

Give it to us in point form ... 1 to 10, like an accountant would do it.

I can visualise that the coefficeint of drag will differ for various parts of the body ... high through the shoulders missing all vitals, through the ribcase missing all vitals, just behind the shoulder but through the lungs only and then say a solid heart shot smack on the lower shoulder. Or even a pure meat shot through the buttocks.

I can also visualise the expansion and contraction (back to permanent wound size)of the flesh and that the so called wave is much much less than in water (as it is not the same as water) and that its effect on killing can for all intents and purposes be ignored.

Killing depends on the damage to life important organs, bleeding to death over time (short vs long)and hitting of the CNS.

Gunyana has commented on shot buffalo when the heart is in the sistolic phase (full of blood)and the bullet hits it at that point in time. The heart burst and beast will drop intantly. Autopsies with shots like this show burst hearts that differ from the normal which is either a rapture or or a clean punched hole like with a solid.

Anyway, I am sure you can put all these things in much better perspective, as you have studied these things like I have studied accountancy. So do not keep the AR family in agony and allowing to make mistakes ... give it to us straight the way it is the way the medical profession sees it.

Take care
Chris

quote:

Whereas a Tsunami wave could boule one over and even drown a person......

The one thing we know is that a high-velocity bullet will not boule a buck over nor drown it.

I am struggling to understand this analogy and sought clarification in previous posts by Chris and some research on the term "boule". I found this:

From Wikipedia, the free encyclopedia.
* A boule can also refer to a round loaf of white (often sourdough) bread, from the French word for 'ball.'
* There is also a game called Boules where large balls are thrown at a small ball

This reference to balls reminded me of a post by Chris where he also referred to balls and said:

quote:

Assume we roll the lead ball, weighing 10 pounds, in the direction of a cow at 5 mpu, laying in the kraal.

What would happen if 73.3 lb-ft/s hits that cow?

A mere bump and that is it!

More research around the unknown term "mpu" at that time, brought the following clarification:

"It is ironic that the experiment devised to test the theory of mpu is based on the game of Moksa (rolling the ball at the cow). The ball is called the sadile dengwa or sd for short and the cow selected for the game would be awarded to the winning player as a moomentum. Players of the game, which usually lasted seven days, are called bekkas. These games are generally accompanied by much informal banter and insults are passed between players as part of the distraction strategy."

Unfortunately the analogy still escapes me as I do not follow this fixation around balls.

quote:

Originally posted by Overkill from sweden:
Hi!
I have heard about the "shockeffect" and "hydrochock" made by the temorary cavitation of the bullet when it is inside the animal.
And I have heard that the temporary cavitation the "temporary hole around the bullet" start when the bullet velocity is over 2650FPS inside the animal!???
So bullets with velocity under the 2650FPS will not make any temporary cavitation in the animal??
And can not make the shock effect?
Is there any bullet velocity limit for the temporary cavitation?
//OK

Go to the Barnes web site an order the free DVD which gives a very good illustration of what happens.

If ya'll will just shoot em where it counts, you won't have to worry about all this fancy physics stuff.

Interesting discussion, however, I do not see field experience being shown here, so here goes. My experience with "Hydrodynamic shock" or "Hydrostatic Shock" comes from the following cartridges = .270 Winchester (130 grain Silvertip and 140 grain Ballistic Tips) , .257 Weatherby with 87 factory loads, and .243 Winchester with 85 grain Sierras. The .257 and .243 would messily pulp a Woodchuck at any range from 50 yards out to 425 yards, while a .222 Remington or .22 Hornet would just zap the critter and actually leave edible meat. The .270 Winchester is another case entirely. The .270 leaves a relatively small (read normal) wound channel, HOWEVER, the .270 also leaves a tremendous amount of blood shot meat, extending a long, long, way from the wound channel. This excessive meat damage is what caused me to stop using the .270 when I became a dedicated meat hunter, for example = loosing both shoulders on a buck struck exactly in the center of the chest (head on shot), or the same experience with a broadside shot. Last weekend I had my memory jarred while field dressing our deer (two for each of us). The two deer shot with my meek little .260 Remington gave more usable meat that the two shot with a .270 with those new Ballistic tips. In fact the entire carcass of either .270 victim appeared to be completely bloodshot, despite a wound channel quite similar to that formed by my "little" .260 Rem.

I do not claim to be a forensic expert, but I think that blood shot carcass is what the Hydrodynamic Shock theory is all about. The difference between a Weatherby and a routine .30-06 i the same. Either round kills, it is just a question of the violence with which the deed is done. The same goes for the argument between the 5.56mm and the 7.62x39mm, both do the job, only in different ways.

LLS

sierra2,
Overkill posted this question in European Big Game as well. The field experience you are looking for is there. Not surprisingly, it concurs with what you have said here.

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Ok ok, I'll wade in with my 2 cents worth!

1) Bullet velocity is an important factor in wound size and form.

2) The effects of increasing velocity are not constant- they increse in sudden setps apprximately- but not exactly equal to the speed of sound.

Right, my personal observations from autopsies on people and game.

A bullet fired into a dead animal or person causes significantly less bruising than one fired into living flesh. It is always possible in an autopsy to id bullets that were fired into a person after the heart was destroyed or the brain scrambled.

Some animals are more suceptable to "hydrostatic" shock than others. Cats are notorious. People are very succetable - unless they are hyped up or smoking something.

The "wounding" effect of high velocity induced tissue damage does not necessarily translate into "stopping power".

I was present at an autopsy of a "war Vet" who was shot down attacking a farmer three years ago. The 9mm fmj bullet passed through the gooks chest without hitting a major blood vessle, lung or heart. Said gook proceeded to axe farmer, who was rescued by his workers. Two days later said gook died of "respiratory Embarassment" as the pathologist termed the effects of bruising on the heart and lungs.

From the military - As bullet velocity exceeded about 1200fps the bullets effect on bone and fluid filled organs became noteworthy. Bone shattered instead of just breaking giving rise to secondary projectiles. Fluid filled organs tended to burst.

As impact velocity went above 2250fps explosive wounds were noted. During the Boer war there were many accusations by the brits that the boers were using soft point hunting ammo in their 7mm mausers. The military doctors had never seen explosive wounds before (the .303 ammo gave only 2150fps) American and German doctors working on both sides finally nailed the "problem" down to velocity. (NB by 1900 some Boers were using soft point ammo in their rifles as they had run out of ball, but the problems and solution had been worked out before then)

The Brits, in the light of their findings went onto the Mk VII ammo - V= 2450fps, and an unstable bullet designed to tumble and increase the wounding effect far beond the 10om or so range at which velocity alone would cause explosive wounds.

I was not particularly impressed with 55 grn .223 ball on p[eople on our anti poaching ops. I generally carried a HB FAL or BREN as the heavy fire support, but Charlie Haely ( Head of Zim's Forensic Ballistics lab) Steve Edwards, charles magna and others stayed with their AR15's/M16's but using IMI 55grn Hollow point ammo. On the basis of what we found out on poachers, the Zim police began re-arming with .223 rifles (until they ran out of money)

All that said- I took an AK round through the right shoulder at a range of 3 yards. There were certainly secondary bone projectiles flying arround my chest, and the bruising ran almost to my elbow and down to my waist. It hurt, and made me drop my rifle but did not stop me drawing my revolver. - I am still here. Would a 7.62 Nato have saved the poachers life? Don't think so, but I would probably have lost my right arm.

So, big bullets, going reasonably fast work! Small bullets need hollow points or other fancy bullets to help copmpensate for lack of size no matter how fast they are driven - IMHO

quote:

I do not claim to be a forensic expert, but I think that blood shot carcass is what the Hydrodynamic Shock theory is all about. LLS

I disagree. I have dropped several deer sized animals with both x-bullets as well as Gerards bullets (6 and 7mm cal impacting at 3,000 fps or above), without any significant amount of blood shot meat. Without impacting the CNS directly. As a matter of fact, that is why I shoot copper bullets.

My conjecture is that the solid bullets maintain velocity inside the animal far longer, and continue the "shock wave" for a longer duration: the maximum amplitude may be smaller than with a rapidly expanding soft point, but the duration increases effectiveness.

Question for Ganyana and Alf: what do you think would have been the effect if the AK round had been a 223 round (with 1/3 higher impact velocity)?

Somewhere in the equation, energy expended inside the organism has to come into consideration; if we hold energy constant, is the smaller, faster projectile more or less effective? FWIW, Dutch.

Alf,
It has not ocurred to me to shoot a dead animal again but I take your point that blood shot meat will only be seen as a result of shooting a live animal that has blood pressure.

quote:

If you look at modern trends in military small arms munitions the world is moving away from ultra velocity projectiles and moving more towards heavier and slower projectiles.

I presume the reason for this is that the high velocity rounds are causing unacceptable levels of bullet failure through fragmentation of the fragile projectiles?

Very interesting question.

An old police man I used to know used to talk a lot about this very thing. He said that while the extra speed of the .223 was nice, a bigger .308 bullet would "anchor" a target faster.

His experience in the military and law enforcement was that the bigger bores would give better terminal performance than a high velocity small bore.

For Dutch

If I had been hit by a .223? Which .223??? the F.N. "c" that we were issued briefly and the Sig 551's with a 1:9 twist shooting SS109 ball are very inferior in wounding effect to the AUG's and old M16's we used with the 1:12 twist and 55 grn ball

I had a very early AR 15 with a 1:14 twist. My M1 carbine shoots a tighter group at 100m but at close range -oh boy did that rifle make a mess.

Basically, I don't believe any .223 would have stopped me drawing my handgun - ie the wounding effect of that shot would not have "stopped" me. I would like to think I would have still kept going if I had been hit woith .308 ball but not sure.

Afterwards though...The 55grn bullets caused imence sloughing away of dead flesh. Ie meat actually destroyed rather than just bruised. The 62/64 grn bullets never caused that on any prinoners we took.

so- A 55grn bullet from a 1:14 twist would have cost me my arm. A hollow point from a 1:12 twist would probably also have done so. An SS109 ball would have been no worse than an the AK.

As the range increases, the wounding effect falls off very quickly with both the .223 and the AK.

I took a bullet through my rt leg fired by one of my own game scouts 6 years back. Range was about 180m. A ceaner hole would be hard to find, and when someone asks to see the scar it is pretty ard to find!( the entry and exit holes are as faint as the ones from a .22 that I put through my hand as an 11 year old) Certainly caused much less trauma- true it was a flesh only wound- no bone hit, and although I fell down on being hit I was soon up and was able to organise clearing up after the contact and drive myself to hospital - where they changed the dressing, gave me an atibiotic, and told me to see my GP in a week.

We saw similar things on poachers taken prioner. Anything beyond 50-60 m range produced significantly less severe wounds than those causes at normal contact distances.

I will ask Nikudu to put up an article I wrote some years ago on shotgun effectiveness based on our fist 18 contacts and the subsiquent autopsies. After those initial contacts most swithched to .223's and I took to carrying an LMG. (either the HB Fal or the Bren)

Why didn't I choose the RPD? of which we had plenty. RPD's are no good on elephant or buff at night! (almmost all contacts were at night)

We had been working with the Brit and NZ SAS units and American Deta operators- who all used .223 - very effictively I must say. Still they all used IMI hollow point ammo in their rifles and when we switched to .223 we did the same!

hi Ganyana
I am glad you survived your byllet wounds. my question is about the feeling of pain when get shot. i was shot in the leg too ,but with a 22 lr . the strange thing was i didn't feel a thing before a couple of minute or maybe be more. i discovered the wound by looking at my pant which was red of blood. the pain came much latter. i wonder if the nerv system collapses at the place were bullet enters?
anybody else with more experince please? maybe why the animal runs without showing a feeling of pain at the bullet impact?.
regards
yazid

Oh I felt the one through the shoulder all right! Mind you an AK spitting fire 3 paces ahead lets you know sound wise as well- he fired 12 rounds at me.

The one in the leg stung and made me drop- I was running towards a gang of poachers and a game scout way out on the right had seen them and was fleeing the scene as fast as he could with his AK pointing backwards over his shoulder. - It was Friday the 13th - I got straight back up though, and thought it was a ricochet or some such - Have had harder blows on the shooting range from pistol bullets bouncing back off badly angled plates.

Talking to two of my mates who were both badly wounded- Charley Haley took a burst from an RPD, an old yank bazooka rocket hit a tree next to him and a couple of grenades within a meter. He lived- they died, but he lay alone in the bush for 3/4 of an hour in absolute agony before help arrived. He initiated the contact and was pumped up with adrenaline before he was hit.

Blaze was shot three times in the chest with an AK. He says he knew he was hit, but was able to keep going, and there was no pain until much later ( it was 2 days before he got help) The bullets had hit the right lung but only broken one rib. Also he was fully charged up and fighting for his life long before he was hit.

I think pain is individual, how much adrenaline is released, and weather a major bone is broken.