Long Range Hunting Online Magazine Hydrostatic shock, what's your opinion?
 Home LRH Store Forums Long Range Rifles Articles Reviews Group Hunts Shooting Classes G7 Ballistics Calculator Rules & FAQ Register Search Today's Posts Mark Forums Read

 Long Range Hunting & Shooting

# Hydrostatic shock, what's your opinion?

#1
12-20-2009, 01:51 AM
 Gold Member Join Date: Sep 2009 Location: SW MT or noVA Posts: 986

Hello everyone,

I'm curious as to what you think about hydrostatic shock. Ive read quite a lot and it seems to be logical but yet there are studies disproving it.

Have any of you witnessed a kill you believe to be hydrostatic shock? (abdomen shot causing bangflop) or such.
I watched an episode of mythbusters where they blew open a safe by suspending a small explosive charge in the middle and filling it with water. The water then transfered the force to the door ripping it straight off. They repeated the experiment with no water in the safe and the charge did absolutely nothing. Also, the water transfered the force to the objects inside the safe, breaking them aswell.

I would think a big bullet going real fast would bring this about, anyone land a gut shot on an animal with something like a 30-378? be interesting to hear what it did.

Oliver

#2
12-20-2009, 01:51 PM
 Platinum Member Join Date: May 2008 Location: South of Canada and North of Wyoming Posts: 6,068
Re: Hydrostatic shock, what's your opinion?

I used to use the term hydrostatic shock until this past year when I learned in another forum in a discussion of the same topic that hydrostatic shock is a misnomer.

From Wiki, the definiton of hydrostatice...

Quote:
 Fluid statics (also called hydrostatics) is the science of fluids at rest, and is a sub-field within fluid mechanics. The term usually refers to the mathematical treatment of the subject. It embraces the study of the conditions under which fluids are at rest in stable equilibrium. The use of fluid to do work is called hydraulics, and the science of fluids in motion is fluid dynamics.
Note the last sentence regarding hydraulics.

Here is a definiton of static...

Quote:
 static (stat′ik) adjectiveof bodies, masses, or forces at rest or in equilibrium not moving or progressing; at rest; inactive; stationary
So the more correct term is hydraulic shock.

Now that we have that out of the way, let's look at the safe experiment. What's different about a safe and animal flesh? Elasticity or the lack of it. Materials that dont bend or flex wiil break more readily tham materials that are elastic or flexible. So the safe experiment does not apply to hunting. It does show that that liquid transmits pressure better than air because it does not compress.

Animal tissue is is elastic and it will stretch and return to it's former state if it's not stretched beyond it's elastic point. This aspect of terminal balisitics is know as temporary wound channel. Most "shock energy" transmitted through an animal's body is absorbed. If there is enough hydraulic shock to exceed the the elastictic limits of the tissue then it will not return to its former state and we have permanent wound channel. More fragile tissue such as lungs and liver would be more suspetible to permanant damage then lets say the heart, flesh, etc.

Here is where a bullets design is important. The shape and velocity of the bullet as it passes through an animal will detremine how much permanant damage is done. The more flat/square the frontal area is and the faster it is moving, the more it will deystroy tissue by exceeding the tissues elastic limits. This in turn cause hemoraging, which in turn causes low blood pressure, which in turn causes a lack of oxygen to the brain, which in turn causes death. the more flat/square surfaces of monmetal bullets and blunt hard cast bullets do more damage than rounded front mushroomed jacketed bullets which do more damage than spitzer shaped non-expanding bullets. The later doing very little damage at all unless it directly strikes a critcal organ such as the heart or spine, etc.

You will often hear or read arbitrary minimum KE numbers needed to kill a particular species of animal. These minimum energy numbers have nowhere near the required energy to deystroy organs or inject any letahal hydraulic shock to the animals system. What they better represent is the "momentum" the bullet has to penetrate the animal which is based on the bullet's velocity, mass and shape. The bullets shape as it impacts and passes through is dependant on its design and construction. The more flat and greater the frontal area, the more momentum it will need to penetrate and the more permenant damage it will do. The bullet will also loose some energy when it is deformened on impact which means it will loose some velocity/momentum.

In the final analysis, hydraulic shock *usually* does not do much signifacant damage to the animal other than the permenat wound channel created by the bullet, because of the elasticity of the animals tisssue that absorbs the hydraulic shock and returns to it form. The best strategy for killing animals quickly, other than destroying the CNS, is to put a hole through it where it will loose the most blood the quickest and the larger the better. Animals are not "shocked" to death. They die as a result of lack of oxygen to the brain period. In some rare cases it might be possible for hydraulic shock to cuase the heart to fail which in turn stops oxygen to the brain. But that's all complex and difficult to quantify.

Last edited by MontanaRifleman; 12-24-2009 at 12:24 PM.
#3
12-20-2009, 01:52 PM
 Gold Member Join Date: Oct 2003 Location: Lizton, IN Posts: 747
Re: Hydrostatic shock, what's your opinion?

Well, an animal is different from a bag/box full of water but all of the energy that a bullet leaves inside an animal has to go somewhere; it doesn't just disappear. Anyone who has had a bullet expand well in an animal is familiar with the massive damage that occurs many inches away from where the bullet actually passed. Call it "hydristatic" shock or just energy dispersion, the name is unimportant but the energy delivered from a bullet can obviously do a lot of damage outside the actually bullet path.

Last year I shot a doe with a muzzleloader. I did not have time to range her so held high, and hit high. The bullet was a bonded Shockwave and left no sign of expansion as it passed through the very tops of the lungs and under the spine, touching nothing except the skin on both sides and the tips of both lungs. At no point did it touch the spine or any bone connected to the spine. Yet the dead dropped dead as a doornail when the bullet hit her, never even flinched. I jogged the 140 yards up to her immediately, and she was done when I got there, I never observed ANY movement and she was always in sight. Obviously the energy from that bullet passing was enough to disrupt her spine permanently, even though it passed through soft tissue 3 inches away.
#4
12-20-2009, 03:30 PM
 Platinum Member Join Date: Nov 2008 Location: SW Montana Posts: 5,514
Re: Hydrostatic shock, what's your opinion?

I shot a few deer with my 22-250 with 55gr v-max bullets at around 400yrds and saw some very interesting result. All hits were ahead of the diaphragm and I found the intestines and stomach blown up and bloody, I contributed it to hydraulic action. The animals ran maybe 30yrd and then tipped over, the bullets blew up and did not actually do much direct damage but from one end to the other all the organs were torn or damage indirectly.
This year a friend shot a bull elk with a 300WBY and 165 Barnes, the hit was just above the heart and trashed the lungs but the bullets blew up not reaching the off side. The gutts in this elk were torn up, but it did not directly die from it.
In both cases the animal were feeding in alfalfa field and they where tight, not like animal shot that have been living in the mountains on grass.
#5
12-20-2009, 04:40 PM
 Gold Member Join Date: Sep 2009 Location: SW MT or noVA Posts: 986
Re: Hydrostatic shock, what's your opinion?

Bigandgreen, I have had an experience like that aswell, I shot a doe in the neck at about 80yards with a 150grain round nose bullet out of my .308win going relatively fast and the brain was shot out through the eyes, I too attribute this effect to hydraulic shock. I beieve this is also how Berger VLDs perform so well.
#6
12-20-2009, 04:52 PM
 Gold Member Join Date: Sep 2009 Location: SW MT or noVA Posts: 986
Re: Hydrostatic shock, what's your opinion?

MontanaRifleman:
I'm aware the normal way of dispatching game is to disrupt te bloodflow and oxygen supply to the brain. I'm wondering if it would be reliably faster to shoot an extremely fast bullet to cause massive shock and temporary wound channel trauma to kill the animal. Like aiming for the neck-spine junction and even if you miss a bit the shock will kill the game. Will test this shot next time I hunt deer.
#7
12-20-2009, 06:12 PM
 Silver Member Join Date: Feb 2007 Location: Miles City Posts: 191
Re: Hydrostatic shock, what's your opinion?

A few years back, I made a somewhat bad shot on a big whitetail. 278 yards away. Shot was low and a few inches infront of the hinde quarters. Deer didn't even quiver. Hit/Drop. I saw no signs of any damage to any major arteries, vital organs, or spine. No bone either. 300 RUM 200gr. Accubond 3095fps. Don't have any real reason on how the bullet killed him expect for massive body shock???? Same thing happened this year with the wife's buck except she hit it in the lungs. Other than that, not much other damage. Hit/Drop. ????

J. Sibble
__________________
I don't hunt.....I harvest.

 Bookmarks

 Thread Tools Display Modes Linear Mode

 Similar Threads for: Hydrostatic shock, what's your opinion? Thread Thread Starter Forum Replies Last Post Fergus Bailey Rifles, Bullets, Barrels & Ballistics 8 10-22-2010 09:47 PM angus-5024 Reloading 3 08-26-2009 09:01 AM BigDaddy0381 Reloading 8 05-30-2007 05:45 PM Derek M. Rifles, Bullets, Barrels & Ballistics 23 02-17-2005 09:53 PM missedshot Rifles, Bullets, Barrels & Ballistics 2 12-22-2003 03:40 PM

All times are GMT -5. The time now is 07:44 PM.