cart SHOPPING CART You have 0 items

Discussion Forums

Search forums
Forum Index > Rifles general discussion > Hydrostatic shock

Hydrostatic shock

11 Mar 2016
@ 12:06 am (GMT)

David Gray

So, I was on another blog, board, website..whatever. One of those that is mostly about the M4 carbine. And clones....but that's another story.

One of the members asked about if there were such thing as Hydrostatic shock. I sent him a link here. But apparently the boys at the M4 site have made up their mind that there is no such thing as "hydrostatic shock". It's a myth. Fudd science. Witchcraft. Etc.

It stirred up a fairly big crapstorm and the thread was shut down. Ask, answered and debunked numerous times. Plus they seemed to think that the OP, and me also, were just trying to stir up trouble.

This is not the first "run in" I've had at this particular site. I was chased around the board by a moderator with him stepping on every post I made. And finally banned for 4 mo's for questioning their now infamous, what was is called?.....Standards? for the AR15 platform.

Anyway. I know I may sometimes ask ignorant questions. I do appreciate the civility and patience shown by members here. It's sure not like that everywhere.

Oh. Probably put this in the wrong section!


11 Mar 2016
@ 02:24 am (GMT)

Martin Taylor

Re: Hydrostatic shock
I can give a great example of shock David that l have sent through to Nathan, it is very real and extremely effective!

Young Sambar deer taken with 9.3x62 250gn RN, 20-30 yard lower neck shot. Missed anything that mattered including, spine, arteries, etc. no blood, went in just clipping the wind pipe it was that low.
Result, instant death without even flinching.

I'm glad you feel free to ask questions on here, many of us want to help out in some small way, just as Nathan helped us. The cartridge book explains how projectiles kill in great detail.

Let them stick their heads in the sand mate!
11 Mar 2016
@ 02:37 am (GMT)

David Gray

Re: Hydrostatic shock
I don't know what it is but the firearms community can be kind of....closed minded? Opinionated for sure. Stuck in the past? No doubt a very close community. And very cliquish.

I've been in the "firearms community" since I was 10 y.o. going on dove hunts. Deer camp at 12. Skeet shooting at 14. And even that young I definitely noticed it.

It's a shame. We are all in this, or should be, for the same things.

Don't get me started on the Bow Hunter/gun hunter clique. Even worse, around here, is the dog hunter/non dog hunter bunch.

And now we have the bait/don't bait deer feud. Hell! I just wanna have fun!
11 Mar 2016
@ 03:05 am (GMT)

Thomas Kitchen

Re: Hydrostatic shock
this forum has always been a good place to learn for me.
most people seem to be like minded and helpful as martin has said.
its one of those places that there's no such thing as a stupid questions or a silly idea.

i do know that Nathan has worked hard to keep this forum both positive and helpful im very thank for this its good to be able to post a question without the fear of getting hammered by some keyboard warrior
11 Mar 2016
@ 06:11 am (GMT)

Michael Rayner

Re: Hydrostatic shock
I wouldn't even waste my time with a bunch of mall ninjas with their poodle shooters, life's too short
11 Mar 2016
@ 07:28 am (GMT)

Warwick Marflitt

Re: Hydrostatic shock
"Bigots" Is the world still flat ! Hopefully they'll fall off at the other end?
11 Mar 2016
@ 07:20 pm (GMT)

Nathan Foster

Re: Hydrostatic shock
I think one thing we have to be careful of is the actual wording. The term hydrostatic may or may not be the best word. The word itself refers to water (hydro) and electrical nervous impulse (static) and may not be the best selection of words but it was named thus many decades ago. The people who originally came up with this name were trying to explain a shock wave passing through water as a medium, interrupting electrical nervous activity.

I have deliberately argued this around with myself and with my veterinarian friend and book editor to look for holes in my own work but based on field results, it simply is what it is and the term fits the bill even if there are other elements involved.

If we take a boxing K.O as an example, the jaw is struck, the brain bounces around inside the skull and although this is a direct force through bone (as opposed to water only), the nervous system will shut the boxer down into a state of unconciousness for internal daignostics and recovery. This may not be a good way to explain what has happened and a neurologist could pull this to pieces but he also knows that such things can be analyzed to absurdity.

When hunting, a very dramatic example is seen (regardless of impact velocity) when the dorsal vertebrae is struck. This will shut the animal down but it will then recover, often unexpectedly, then make a break for freedom or if we are unlucky the animal may turn on us. Those who have had animals awaken and turn on them never forget such things and I am sure they do not give a hoot whether the term is dubbed hydrostatic shock or simply K.O or whatever. The fact remains that there is a difference between actual killing and the effect of rendering the animal unconscious.

We also have to keep hydrostatic shock in perspective. It is a factor that we cannot always rely on as a means to anchor game. If the bullet is too light or too heavy, we may not see this effect. If the bullet is traveling too fast or too slow or if the bullet is too stout, we may also not see the result we were hoping for. Nevertheless, it can be a very useful method of securing game quickly when it does occur.

Not all animals react in the same way either. Some animals collapse, some jump into the air and pass out as they come down, some drop but the recovery is within a second and so they try to rise from their knees but the action of doing so and the drop in blood pressure causes them to pass out so you see a "drop, rise, drop' effect.

We seldom see hydrostatic shock in an AR-15, regardless of the chambering selected.

We also need to keep in mind that Hornady have performed their own tests. Hornady use different wording and have been studying some different mechanisms such as blood pressure spikes in the brain. In other words, they understand that this effect does occur and have been spending time studying the various reasons why.

Guys, my email has been out the past 24 hours. I will try to get this fixed today but when it does come through, I will be 300-400 emails behind so you'll have to bear with me over the next few days sorry.
14 Mar 2016
@ 02:04 am (GMT)

Mike Neeson

Re: Hydrostatic shock
The term hydrostatic Hydro - fluid, static - stationary or not moving. So roughly, it means pressure of a fluid at rest. Fluid is non compressible and in a sealed, fixed volume container, transmits pressure changes VERY quickly. A massive pressure change will transmit almost instantaneously overwhelming the nervous system. The body of an animal however, has both solid and hollow organs and the transmission of this shock wave will vary dramatically depending on where the energy is applied. Imagine a bullet strike to the gut - mainly hollow - the effect will be limited, whereas a strike to a more solid area - like the neck - will give a greater propensity for shock wave propagation.
For me this is all theoretical and I have very little "real life" experience to base this on. Just my thoughts on the matter.
14 Mar 2016
@ 02:51 am (GMT)

Mike Neeson

Re: Hydrostatic shock
Just an end note, when the fluid moves - or bursts - out of it's sealed container it is called hydrodynamic. Fluid in motion.
14 Mar 2016
@ 03:23 am (GMT)

Warwick Marflitt

Re: Hydrostatic shock
When a ship hits a wave the wave gets forced aside sending a shock wave of energy into and through the water

Shock Wave:

A shock wave is a strong pressure wave in any elastic medium such as air, water, or a solid substance, produced by supersonic aircraft, explosions, lightning, or other phenomena that create violent changes in pressure. Shock waves differ from sound waves in that the wave front, in which compression takes place, is a region of sudden and violent change in stress, density, and temperature. Because of this, shock waves propagate in a manner different from that of ordinary acoustic waves. In particular, shock waves travel faster than sound, and their speed increases as the amplitude is raised; but the intensity of a shock wave also decreases faster than does that of a sound wave, because some of the energy of the shock wave is expended to heat the medium in which it travels. The amplitude of a strong shock wave, as created in air by an explosion, decreases almost as the inverse square of the distance until the wave has become so weak that it obeys the laws of acoustic waves. Shock waves alter the mechanical, electrical, and thermal properties of solids and, thus, can be used to study the equation of state (a relation between pressure, temperature, and volume) of any material.

A bow wave or bow shock is the progressive disturbance propagated through a fluid such as water or air as the result of displacement by the foremost point of an object moving through it. Viewed from above, the crest of the bow wave of a moving ship is V-shaped; the sharpness of the V is determined by the relative speeds of the ship and of the propagation of waves in the water.

Excerpt from the Encyclopedia Britannica without permission.

I think the bullet traveling through an animal causes the same thing as it displaces the flesh and bone in the way


We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.