Hydrosatic Shock . . . cause and effect
Could we have some discussion / conversation of hydrostatic shock to include perhaps the effects of velocity vs. frontal area of the projectile vs. the construction of the projectile?
Hydrostatic Shock is a reality even if based solely on my observations of wounds in VN and autopsies that I've done on game take by myself or by hunting buddies.
We have all seen the super slowed down films/videos of large animals struck by the projectile ... wherein there is a large rippling effect noted radiating out from the point of impact ... much like the ripples caused by a pebble tossed into a placid pool of water.
When it is an animal body the effects are more devastating and permanent. I believe that is the physical prescursor or indicator of probable blood-shot effects that we can find later.
Noted some animals that dropped in their tracks without spinal or head shocks and others hit with the same bullet/chambering that showed very different effects.
I have recovered game with extensive trauma with graphic "blood-shot" evidence, seemingly hit very similarly to other game without those signs.
I had searched here on the GB Forums and found little regarding same. I'd been given the heads-up regarding observations and studies being carried out by Nathan & Stephanie Foster, and have perused same and gleaned much useful information for my wants and purposes at:
[ http://www.ballisticstudies.com/ ]
I had also done a search through wikipedia for another prong or avenue of approach and found useful information there, to include a snipet that I recall from many years ago, that is as relevant a true today as then:
"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."
- Jim Carmichael[80]
[ http://en.wikipedia.org/wiki/Hydrostatic_shock ]
I had seen reference to research/studies by the US Army Institute of .... , but have been unable to pull up any information from that and them.
Not having the information where we can read and study it is about like people coming to GB inquiring about a firearm and then NOT including pertinent info and photos!
To me if the information is Not available for us to touch, read and study ... it never happened!!! And if it did happen and it is NOT shared, it is maybe worse than if the studies had never been undertaken. JMHO!
Hydrostatic Shock is a reality even if based solely on my observations of wounds in VN and autopsies that I've done on game take by myself or by hunting buddies.
We have all seen the super slowed down films/videos of large animals struck by the projectile ... wherein there is a large rippling effect noted radiating out from the point of impact ... much like the ripples caused by a pebble tossed into a placid pool of water.
When it is an animal body the effects are more devastating and permanent. I believe that is the physical prescursor or indicator of probable blood-shot effects that we can find later.
Noted some animals that dropped in their tracks without spinal or head shocks and others hit with the same bullet/chambering that showed very different effects.
I have recovered game with extensive trauma with graphic "blood-shot" evidence, seemingly hit very similarly to other game without those signs.
I had searched here on the GB Forums and found little regarding same. I'd been given the heads-up regarding observations and studies being carried out by Nathan & Stephanie Foster, and have perused same and gleaned much useful information for my wants and purposes at:
[ http://www.ballisticstudies.com/ ]
I had also done a search through wikipedia for another prong or avenue of approach and found useful information there, to include a snipet that I recall from many years ago, that is as relevant a true today as then:
"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."
- Jim Carmichael[80]
[ http://en.wikipedia.org/wiki/Hydrostatic_shock ]
I had seen reference to research/studies by the US Army Institute of .... , but have been unable to pull up any information from that and them.
Not having the information where we can read and study it is about like people coming to GB inquiring about a firearm and then NOT including pertinent info and photos!
To me if the information is Not available for us to touch, read and study ... it never happened!!! And if it did happen and it is NOT shared, it is maybe worse than if the studies had never been undertaken. JMHO!
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I will be looking at others reply to this topic. I to have seen two different animals hit is almost the exact spot with the same cartridge same bullet and like range show entirely different post impact results. Some have massive PURPLE JELLO around wound and others hardly any . some drop "in their tracks and others run until lungs no longer function to I guess oxygen to the brain. I have never studied brain damage. . Could it be that time of impact in relationship to where in the cycle of a HEART BEAT make a difference blood pressure is sort of a SINE wave. Perry Shooter. 0 -
A life-long work in physics and hydraulics prompts a question.
Was this shock/ripple effect produced in subsonic and supersonic projectile hits, or supersonic only ?
Or was that distinction possible from the observations available ?0 -
AGILE Project is the testing of the AR 15 and I ran across it in the book called The Gun. I think this may be a lead for you to find more information because I believe that the AR does this type of damage. Try the National Archives to see if they have the information you are looking for.
Emmett0 -
A high pressure,shock wave coming off the point of a bullet has to be disruptive to a heart if it passes near or penetrates a major artery. 0 -
Alan,
Think of the body in mechanical terms. Air compresses, liquids (blood, fluid) and solids (muscle, bone) do not. Just like in mechanical applications they pass energy on to the next thing
A lung shot would be like shooting through the passenger door and having the bullet exit the drivers side door. All you did was punch through. Bullet performance is not going to do a whole lot of damage. That is unless it comes apart and throws shrapnel everywhere inside the lung, causing even more bleeding. That said, the minimal amount of damage you did was mortal because the area between the doors depends on vacuum and pressure to move oxygen. The holes prevent that. Untreated the victim will die.
If the bullet hits enough muscle or bone to put a straight shot of energy onto a major blood vessel, then you have 'hydraulic shock' taking place. It always takes place but has to actually hit a point just right to transfer enough energy. From what I learned in Hyperbarics class when I went through dive school back in the '80's, is that it takes about 5lbs of differential pressure to begin doing damage to tissue. When you see purple goo, the 5 lb threshold has been exceeded by a wide margin. But, that doesn't mean that pressure, or hydroshock, was transferred to a vital organ. I mentioned in my first paragraph about lung shots, many GI's survived them because not enough transfer of energy to a critical organ took place. Of course, immediate treatment saved their lives. Something a game animal doesn't have the luxury of.
This is no doubt why many hunters prefer shoulder shots. It's more of a direct mechanical breakdown of the animals structure. He ain't going anywhere with broken shoulders. The shot into solid flesh also increases the chance of hydroshock transferring energy to a vital organ. A neck or head shot immediately stops all communication from the brain to the muscles to tell the animal to move. A hit in most of these cases causes some form of hydroshock to occur.
Just remember though, there are no hard, fast rules how it happens. In order for it to damage far away from the impact site, it has to hit a blood vessel, (or in the area) just right. Very small degrees of difference separate huge results in that arena.0 -
A friend I was hunting with told me he killed a doe with a .270 & a shot to the base of the tail.(broadside shot, not a texas heart shot)
He said the shock wave from the bullet traveled up her spine and killed her.0 -
More likely bled her right out. However, if he hit the spinal chord that would give the shock that would neutralize her in very short order. 0 -
Thanks to everyone for the information and discussion. Appreciate the leads also. 0 -
I'll add my two bit's worth here----I got involved with high velocity bulletts way back, when Roy weatherby was beveloping his mag. cartridges, Being an engineering type, I subscribed to the E=MC sqd. formula. I also believe that a bullet that passes completely through does not transfer all of it's energy to the animal, but carries some amount on down range. Having said that, most of my kill's have been on mule deer, and elk, mostly with 30-06 hand loads pushing Nosler 150 - 180 grain partitions. Nearly all kills were instant with death being immediate. Necropsies, as in skinning, cleaning for the freezer, etc showed massive amounts of "blood shot" tissue which had to be discarded. BUT, Never a lost animal. I just happen to be color blind, and do not see blood at all, on a trail, so 2' blood trails suit me fine. Now go to a recent Black bear hunt in Alberta, shooting a Marlin Guide gun, in 45-70, at 20-30 yard, much larger frontal area, much lower velocity. Tissue damage was as much, mabey more than described before on the mulies etc. As a matter of fact, once the hide was removed from the blackie, the guide/outfitter stopped, and everyone present had to see the amt. of damage to Mr. Bear. It was probably the most I have ever seen. All of these kills were instant, with huge amounts of tissue damage. On another hunt for Pronghorn, in Mont. with .264 Win mag. 100 gr Nos Balistic tips, loaded HOT, 385 yard broadside heartshot---Little to no tissue damage. Instant kill. I give up, you tell me. 0 -
Point of clarification. It seems to me, the conversation here has been about "hydraulic" shock, rather than "hydrostatic" shock. The OP references Nathan Foster's work (Terminal Ballistics), where these definitions are given, although I'm sure he didn't come up with these himself:"Hydraulic Shock is the civil engineers term also known as water hammer but in terminal ballistics context refers to the pressure of accelerated fluid particles that create the temporary wound channel.
Hydrostatic shock transfer refers to the effect when shock waves travel through flesh to distant nerve centers, disrupting their ability to emit electrical impulses." (Practical Guide to Long Range Hunting Cartridges, 2nd Edition, page 8).
From my reading of some of this material, impact velocities pay a huge role with hydrstatic shock diminishing significantly below 2600 fps. Animals tend to drop in their tracks with hydrostatic shock, whereas, they can run for a significant distance under just hydraulic shock. Lots of factors impact all of this, of course.
Or am I missing something?Rick
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