Hydrostatic shock, what's your opinion?

[spiaailtli]

I researched this for about 20 years and found some interesting information. Is there such a thing as hydrostatic shock (or whatever you wish to call it)? Yes.

To further complicate things I discovered through a University study on spinal injuries that in four legged critters the walk/run function is controlled 80% in the spine and 20% brain, unlike humans where it is controlled 100% by the brain.

I learned there were 3 studies (that I'm aware of) with high volume kills under libratory conditions and all DRT kills resulted from the same function. A couple of lesser studies in which animals where shot with a wide range of calibers and bullet styles also resulted in the same findings.

There was also one study I found in which at least one person was shot thru the heart and the results recorded.

An animal with the heart completely destroyed still has brain activity for 19 seconds. A deer can cover up to 300 yards in that amount of time.

Most hunting bullet designed is counterproductive to DRT kills.

In my mind one final piece of the puzzle needs to be answered. A device needs to be built that records all phases of an animal's heart beat with a variable control to cycle through the high and low range. This device needs to be connected to a gun so the precise triggering of the weapon can occur at the proper time. The shot must happen on an unsuspecting animal and the bullet placement should be lung only. Record the number of DRT vs. non DRT over the cycle of the heart beat. My theory is it more about the position of the valves and back pressure that causes the vessels in the brain to burst.

This is much the same as adding the phase of the cycles in an electrical signal.

BTW, there were studies done by universities and the FISH & Wildlife departments in which hunters where placed by officials and not allowed to move. After shots were fired all data was collected and distance to the animal was recorded. Hunters were allowed to use whatever caliber that wanted but data was recorded on type of ammo, caliber, distance to the animal at the time of the shots, etc. There were some very clear winners when it came to bore size and bullet types for DRT kills. J

 

[liltank]

I researched this for about 20 years and found some interesting information. Is there such a thing as hydrostatic shock (or whatever you wish to call it)? Yes.

To further complicate things I discovered through a University study on spinal injuries that in four legged critters the walk/run function is controlled 80% in the spine and 20% brain, unlike humans where it is controlled 100% by the brain.

I learned there were 3 studies (that I'm aware of) with high volume kills under libratory conditions and all DRT kills resulted from the same function. A couple of lesser studies in which animals where shot with a wide range of calibers and bullet styles also resulted in the same findings.

There was also one study I found in which at least one person was shot thru the heart and the results recorded.

An animal with the heart completely destroyed still has brain activity for 19 seconds. A deer can cover up to 300 yards in that amount of time.

Most hunting bullet designed is counterproductive to DRT kills.

In my mind one final piece of the puzzle needs to be answered. A device needs to be built that records all phases of an animal's heart beat with a variable control to cycle through the high and low range. This device needs to be connected to a gun so the precise triggering of the weapon can occur at the proper time. The shot must happen on an unsuspecting animal and the bullet placement should be lung only. Record the number of DRT vs. non DRT over the cycle of the heart beat. My theory is it more about the position of the valves and back pressure that causes the vessels in the brain to burst.

This is much the same as adding the phase of the cycles in an electrical signal.

BTW, there were studies done by universities and the FISH & Wildlife departments in which hunters where placed by officials and not allowed to move. After shots were fired all data was collected and distance to the animal was recorded. Hunters were allowed to use whatever caliber that wanted but data was recorded on type of ammo, caliber, distance to the animal at the time of the shots, etc. There were some very clear winners when it came to bore size and bullet types for DRT kills. J

Okay, I'll bite, what were the clear winners in both bullet and caliber? This will be interesting to hear. I always figured the deer I shot at were so amped up by adrenaline that nothing less than a head shot would be a DRT. I have only ever hunted in the woods, so deer are generally pushed.

Tank

 

[jwp475]

Hydrostatic shock, caused by high velocity is BS and an incorrect term. Hydraulic pressure created by a high velocity bullet is real and the correct term

I recomend this book to anyone that believes in "Hydrostatic Shock". Lear the correct terminology which is "hydraulic pressure". Central nervous system hits are dramatic and instanous, but do not need "hydraulic pressure" to be affective. Secoundary fragment wounding does not happen below 2000 FPS and not always at 2000 FPS
The bullet type and performance are more important than caliber to a certain extent

 

[theodore]

.....There were some very clear winners when it came to bore size and bullet types for DRT kills. J

This is interesting. What are they?

 

[Pdvdh]

Hydraulic shock or Hydrodynamic shock would probably be better descriptors.

I read an article written by Jim Carmichael (used to be - maybe still is - Gun Editor with Outdoor Life). In his article, he presented the findings of bison or cows (it was actually cape buffalo) that were culled with high powered center fire rifles on a ranch setting. These animals were center-shot through the rib cage with broadside hits, best as I remember. A person might be able to do a Google search and find the article. These animal's reaction to the bullet were observed and recorded. After the cull, veterinarians performed pathological examinations (autopsy) of the animals. Some percentage of the animals dropped at the shot - instant lights-out deaths. Others died over variable periods of time, same as big game animals do in response to similar bullet hits. The interesting part? All of the animals that expired instantly were observed to have suffered massive strokes. Vessels and arteries ruptured in their brains, and it was more or less concluded that the hydraulic pressure peaks that were transmitted through the blood vessels and arteries overpressured and ruptured arteries/vessels in the brain. Mr. Carmichael surmised that if the timing of the bullets' impact coincided with the peak animal blood pressure that the added hydraulic pressure might be enough to kill by massive stroke. While another animal stuck very similarly, but when blood pressure was at a lower level might avoid massive stroke, and not produce an instant body-slam kill.

Here's a link to the article authored by Jim Carmichael that I referenced in the about post:

Knockdown Power Some calibers always seem to flatten game. Here's why | Outdoor Life

And here's the section of the article that described the results and conclusions from the autopsies:

"NEW EVIDENCE

This epiphany came about a couple of years back when I was passing a pleasant afternoon in a bird-watching blind in the wilds of Namibia. A previous guest had obligingly left a few copies of a South African outdoor magazine and as I idly leafed through the pages my attention was arrested by an article on knockdown effect. It was not the same tired old stuff about ballistics and penetration, but the result of a controlled study carried out by professional veterinarians engaged in a buffalo culling operation.

Whereas virtually all of our opinions about knockdown power are based on isolated examples, the data gathered during the culling operation was taken from a number of animals. Even more important, the animals were then examined and dissected in a scientific manner by professionals.

Predictably, some of the buffalo dropped where they were shot and some didn't, even though all received near-identical hits in the vital heart-lung area. When the brains of all the buffalo were removed, the researchers discovered that those that had been knocked down instantly had suffered massive rupturing of blood vessels in the brain. The brains of animals that hadn't fallen instantly showed no such damage. So what is the connection?

Their conclusion was that the bullets that killed instantly had struck just at the moment of the animal's heartbeat! The arteries to the brain, already carrying a full surge of blood pressure, received a mega-dose of additional pressure from the bullet's impact, thus creating a blood pressure overload and rupturing the vessels.

If this is the key to the "knockdown" mystery, it has answered a lot of previously unanswered questions. It's certainly the best explanation of knockdown I've heard yet, but it also poses a new quandary. How do we time a shot to hit on the beat? Let the debate begin."

 

[D.Camilleri]

I got another DRT this year on a 5 point Bull Elk at 550 yards. This time the bullet of choice was the 300 grain Berger sent at 2830 from my 338 rum. I have never seen an elk pile up as quick as this one. Shot was just behind the shoulder, no exit and minimal blood shot on the entrance. I literally saw all 4 legs up in the air while the gun was recoiling. The elk never moved. Since I don't gut my elk, I don't know what the internal damage was or what the bullet looked like and after I heard something chewing down in the trees below the kill, I was a little hesitant to stick around too long after I got him quarted up. My thought was maybe a griz down below and the only way I could hear it was with my walkers game ear. It got my attention enough that the 454 was ready for action when I started throwing rocks. Never saw him though.

 

[SBruce]

Lots of good replies on this thread.

Lots of theories too, some seem very logical some not quite so much.

Rather than a very lengthy listing of all the animals I've personally seen dispatched and unfortunately some only wounded; from varmints to predators to deer and antelope to domestic cattle and horses...........I'll submit this:

If someone thinks hydraulic shock doesn't matter, and is totally unneccesary for a quick kill, then they really need to see how long and far a heart/lung/liver hit animal can go when shot with a FMJ or field tip arrow..........there's a reason such projectiles are illegal here for harvesting big game.

I gaurantee you (been there seen it, unfortunately even did it myself in younger days) a bullet that only punches a hole and doesn't hit bone or shock the CNS at least a little, will usually allow an animal to go for a long long way before expiring.

I think BignGreen and JE Custom said it best, the shock itself may not be what does the killing, but it often knocks them off kilter long enough for the permanent wound to do it's job without the animal running for 400 or 500 yds in the process.

There are also most definately temporary wound channels and shock/stretch of tissue when proper bullets are used. Just watch some slow motion video of shots fired into ballistic gelatin or wet paper or water jugs with handgun rounds, then add a whole lotta energy to the equation for a centerfire rifle.

 

[jwp475]

Lots of good replies on this thread.

Lots of theories too, some seem very logical some not quite so much.

Rather than a very lengthy listing of all the animals I've personally seen dispatched and unfortunately some only wounded; from varmints to predators to deer and antelope to domestic cattle and horses...........I'll submit this:

If someone thinks hydraulic shock doesn't matter, and is totally unneccesary for a quick kill, then they really need to see how long and far a heart/lung/liver hit animal can go when shot with a FMJ or field tip arrow..........there's a reason such projectiles are illegal here for harvesting big game.

I gaurantee you (been there seen it, unfortunately even did it myself in younger days) a bullet that only punches a hole and doesn't hit bone or shock the CNS at least a little, will usually allow an animal to go for a long long way before expiring.

I think BignGreen and JE Custom said it best, the shock itself may not be what does the killing, but it often knocks them off kilter long enough for the permanent wound to do it's job without the animal running for 400 or 500 yds in the process.

There are also most definately temporary wound channels and shock/stretch of tissue when proper bullets are used. Just watch some slow motion video of shots fired into ballistic gelatin or wet paper or water jugs with handgun rounds, then add a whole lotta energy to the equation for a centerfire rifle.

I can assure you that a non-expanding bullet can kill an animal quite dead very quickly, I've done so and seen it done. A flat point solid leaves a much larger wound than does a round nose solid.

The so called "hydro static shock" comes from velocity, the faster the projectile the higher the hydraulic pressure that is created

 

[SBruce]

I can assure you that a non-expanding bullet can kill an animal quite dead very quickly, I've done so and seen it done. A flat point solid leaves a much larger wound than does a round nose solid.

The so called "hydro static shock" comes from velocity, the faster the projectile the higher the hydraulic pressure that is created

I am sure they can in certain incidents. I gaurantee you that they also can allow that animal to run for a looong ways before expiring in other instances.

Before we get too deep into that part of it, what calibers are you speaking of?
Are you talking about cast lead bullets (that do expand some at least) or are you talking about bonded, ultra tough solids that someone might use on dangerous African game. Also, are you suggesting that a bonded solid or armor piercing type round placed in the lungs and not hitting heavy bone will always kill quickly.........?? If so, my experiences and tests have proved otherwise.

Sure, 44 and 45 and 50 caliber lead muzzleloading or hndgun slugs can kill quick because of the large surface area that works to resists movement when it contacts a fluid medium. IMO, velocity alone doesn't quite cut it. Shock waves and tissue stretching within the animal are increased by this resistance to movement, and that resistance increases even more with expanding or large diameter bullets.

Makes sense that flat nose leaves a larger wound than round nose, because there's more resistance to forward movement with the flat nose. It's that transfer of energy that happens when the fluid medium attempts to slow the projectile that causes the most shock or temporary damage. The bigger the bullet diameter, the bigger the resulting permanent wound will be after the shock subsides. The more the bullet weighs, the longer the permanent wound channel will generally be.

LR hunters arent using flat nose bullets, or cast lead slugs, or dangerous game solids. We're using long slender low drag projectiles that need to expand and quickly slow down inside the animal (thereby transfering energy and creating shock) or they'll just pencil through, leaving a very small wound that easily clots up. My whole point being; either shock or a large permanent wound to the vitals is necessary to gaurantee a quick kill.

We've all seen shots from time to time that drop animals in their tracks and wondered later (even if secretly) how could that have happened.........Well, even a blind squirrel finds a nut every now and then. No disrespect meant.

 

[jwp475]

The largest most dangerous animals on earth are routinely taken with solids. Don't confuse so called Hydro static shock with bullet types 2 entirely different subjects.

 

[earplay]

Just if you are interested, Knowledgebase

This guy is local (in NZ) and has dedicated massive amounts of time to researching terminal ballstics in the field. He has more recently started a ´wound database´ to show images of various bullets effect on game at various velocities. Plenty of information and a really helpful guy too.

Matt

 

[Pdvdh]

The largest most dangerous animals on earth are routinely taken with solids. Don't confuse so called Hydro static shock with bullet types 2 entirely different subjects.

But those solids are most often used to target the brain, spinal cord (central nervous system), or the structure (bone) of the dangerous animal's anatomy. Hunters plugging these animals with broadside shots through the ribcage would be way better served with controlled-expansion, high weight retention bullets such as similarly heavy, large caliber, Barnes TSX, Swift A-Frame, etc.

I'm grasping to understand you're communication. I believe the consensus is, and the evidence has proven, that high velocity impacts from expanding bullets which have enough weight retention to penetrate into or nearby vital organs and large arteries and veins within the main body (torso) of game animals can often times kill game animals as if struck by lightning - even when these bullets don't strike heavy structural bone, the spinal cord, or the brain - which are typically targeted when using solids on the largest most dangerous animals on the earth. A simple mid-body impact from a high velocity expanding bullet to the non-structural mid-section of the body has been documented capable of extinguishing life before the animal's torso impacts the ground.

 

[jwp475]

But those solids are most often used to target the brain, spinal cord (central nervous system), or the structure (bone) of the dangerous animal's anatomy. Hunters plugging these animals with broadside shots through the ribcage would be way better served with controlled-expansion, high weight retention bullets such as similarly heavy, large caliber, Barnes TSX, Swift A-Frame, etc.

I'm grasping to understand you're communication. I believe the consensus is, and the evidence has proven, that high velocity impacts from expanding bullets which have enough weight retention to penetrate into or nearby vital organs and large arteries and veins within the main body (torso) of game animals can often times kill game animals as if struck by lightning - even when these bullets don't strike heavy structural bone, the spinal cord, or the brain - which are typically targeted when using solids on the largest most dangerous animals on the earth. A simple mid-body impact from a high velocity expanding bullet to the non-structural mid-section of the body has been documented capable of extinguishing life before the animal's torso impacts the ground.

I several friends that shot there elephants through the heart. Not all are shot through the brain

I have shot Bison with a hand gun and put them on the ground very quickly with a bullet from a revolver and a bullet design to penetrate, not expand including bears and none were central nervous system hits all were in the chest cavit through the clock work

You would not believe the size of the wound channel unless you saw it

I am not diminishing expanding bullet just clarifying that a proper shaped no-expanding bullet kills cleanly as well

 

[jwp475]

But those solids are most often used to target the brain, spinal cord (central nervous system), or the structure (bone) of the dangerous animal's anatomy. Hunters plugging these animals with broadside shots through the ribcage would be way better served with controlled-expansion, high weight retention bullets such as similarly heavy, large caliber, Barnes TSX, Swift A-Frame, etc.

I'm grasping to understand you're communication. I believe the consensus is, and the evidence has proven, that high velocity impacts from expanding bullets which have enough weight retention to penetrate into or nearby vital organs and large arteries and veins within the main body (torso) of game animals can often times kill game animals as if struck by lightning - even when these bullets don't strike heavy structural bone, the spinal cord, or the brain - which are typically targeted when using solids on the largest most dangerous animals on the earth. A simple mid-body impact from a high velocity expanding bullet to the non-structural mid-section of the body has been documented capable of extinguishing life before the animal's torso impacts the ground.

The higher the velocity the higher the hydraulic pressure that is created, that is a fact