What is hydrostatic shock?

[Sheprador1973]

Its raining and I'm a bit bored so been thinking a few things through...

Not the most exciting question ever I know but curious as to what it is exactly (hydrostatic shock). I think I have an idea and a friend tried to explain it to me fairly recently but to be honest I was distracted by the stalk we were on.

Not sure if its relevant, but my first deer was shot at around 50 yards. During the gralloch it was observed that it was a clean heart and lung shot (fortunately). However the liver was totally destroyed and as far as I can remember it was not directly hit. I was using my mentor's gun and ammo and he loads relatively light bullets in .308 so moving pretty fast (110r from dodgy memory).

Just interested from those in the know.

many thanks, P.

 

[NigelM]

Hydrostatic shock, or Hydraulic shock as some call it, is a controversial theory that if a bullet dumps enough energy at enough velocity into a body the shock wave it causes is enough to do serious damage to neurones and internal organs not in the bullets path and cause instant collapse.

I happen to believe the theory. I have found that if TV is greater than 2800 fps I get a very high % of bang flops. Over 3000 fps and it's pretty reliable. Go below 2600 fps TV and bang flops are far more infrequent. However, it doesn't work every time which has led others to come up with different theories to explain the bang flop.

 

[paul o']

This and this explains it well Shocking Bullet Performance - Ron Spomer Outdoors also it has a short vid on the shock wave as a bullet enters in slow more .

 

[Scapegoat]

Another way to give examples if it is shotgun pellets when shooting live quarry. Hit a rabbit or pheasant with a good pattern of pellets and it dies instantly. However, on skinning or plucking it you’ll find the pellets have only penetrated the skin and into muscle. It’s very rare to find any damage to internal organs (although I have often found birds with single pellet fatal headshots). This I believe, is the effect of cumulative strikes which kill through shock rather than damage.

 

[Steve88]

Its the transfer of energy in to a shock wave, traveling thru the body causing trauma. you can pressurise a fluid but you can not compress it. And fluid/ water is very efficient at carrying waves ,shockwaves ,sound waves and the like. Hope that helps

 

[User00001]

Hydrostatic shock, or Hydraulic shock as some call it, is a controversial theory that if a bullet dumps enough energy at enough velocity into a body the shock wave it causes is enough to do serious damage to neurones and internal organs not in the bullets path and cause instant collapse.

I happen to believe the theory. I have found that if TV is greater than 2800 fps I get a very high % of bang flops. Over 3000 fps and it's pretty reliable. Go below 2600 fps TV and bang flops are far more infrequent. However, it doesn't work every time which has led others to come up with different theories to explain the bang flop.

Have you ever considered whether the deer was breathing in or out at time the bullet struck?

 

[NigelM]

Have you ever considered whether the deer was breathing in or out at time the bullet struck?

As i said, it's a controversial theory. Some are convinced that it has far more to do with the rhythm of the heart and whether the chambers are full or empty when the beast is hit. Beasts that are relaxed will bang flop more consistently than those who have pinged you and in which the adrenaline is flowing - a bang flop in these circumstances is very unusual. It's a really complex subject and there is no black and white.

 

[EMcC]

A bit like the bow wave of a boat. A small fast boat will give a very big fast bow wave, a tanker or such like travelling slower but due to it's mass will have a slower bow wave but as much or if not more clout

 

[VSS]

Hydro / hydraulic means it involves a liquid. My understanding of hydrostatic shock with regard to bullet strikes is that the impact sends a pulse or shock wave through the blood carrying capillaries in the area of tissue surrounding the point of impact, causing many of them to rupture, resulting in large areas of bruise-like damage often at some distance from the actual entry point of the bullet.

 

[John Gryphon]

I`ve shot a few deer with them too.

Hydrostatically Stabilised Bullets - Woodleigh Bullets

Woodleigh Bullets - Premium Bullets for All Game

www.woodleighbullets.com.au

 

[Sheprador1973]

Wow. Now very glad I asked as it's clearly more complex than I'd first thought.

From a responsible stalkers point of view I'm guessing (but happy to stand corrected) that it's a positive thing? IF it leads to the quicker/more humane/`bang flop' result.

Would that imply that using a faster projectile...or one with more terminal energy, is the way to go? As long as it's still accurate of course.

Thanks for the replies guys...

 

[NigelM]

Velocity tends to be what does it. The problem with velocity is that it usually comes with quite a bit of destruction. I found that the monolithic bullets were very good, hitting them hard and fast but retaining 99% of their structure and not doing too much damage. I wouldn't want to try 3000 fps with an SST for example. It also depends what species you're shooting, what works on a Roe will not necessarily work on a red. If you're shooting 308 win however a Barnes TTSX at 130 grains should do it, even the 110 grain for Roe.

 

[enfieldspares]

Another way to give examples if it is shotgun pellets when shooting live quarry. Hit a rabbit or pheasant with a good pattern of pellets and it dies instantly. However, on skinning or plucking it you’ll find the pellets have only penetrated the skin and into muscle.

Payne-Gallwey theorised that with high pheasants it was the strike of the pellets that stunned the bird and that what killed it was the impact when it hit the ground.

 

[Freeforester]

"From a responsible stalkers point of view I'm guessing (but happy to stand corrected) that it's a positive thing?"

-Sure, providing you aren't planning to eat it, or try to sell the carcase!

 

[sikasako]

Apparently if you're unlucky enough to be hit by a .500 calibre on the extremetities of your body then the hydrostatatic shock can be enough to kill you outright.

 

[enfieldspares]

I don't know about the .50"Calibre round but, certainly, in the Napoleonic era there was a phenomenon, fatal, of death from what was known as "wind of ball" from having a large calibre cannon ball pass by. But that can't have been any sort of shock effect.

 

[Alantoo]

Velocity tends to be what does it. The problem with velocity is that it usually comes with quite a bit of destruction. I found that the monolithic bullets were very good, hitting them hard and fast but retaining 99% of their structure and not doing too much damage. I wouldn't want to try 3000 fps with an SST for example. It also depends what species you're shooting, what works on a Roe will not necessarily work on a red. If you're shooting 308 win however a Barnes TTSX at 130 grains should do it, even the 110 grain for Roe.

That is interesting...I guess the "double the mass double the energy, double the velocity quadruple the energy" principal applies.

But as you said earlier it is not black and white. Placement seems to trump all.

The "what works on a Roe will not necessarily work on a red" point though I am intrigued by in this context. Given we are always reading on here that .243W is enough for any deer in the UK...

I have been working up a load of 110gr TTSX in .308 W and they are travelling at 3200fps-is. Is there any reason they would not be as effective TV-wise as a smaller calibre similar weight bullet travelling at a similar speed on larger quarry than Roe? I was comparing the relative speeds of 100/120gr 6.5mm Creedmore TTSX which presumably are not restricted to Roe? I realise the BC and longer range advantages/differences.

I had been thinking they would work well for my Roe, Fallow and Muntjac at <150metres.

Alan

 

[Matt.]

Apparently if you're unlucky enough to be hit by a .500 calibre on the extremetities of your body then the hydrostatatic shock can be enough to kill you outright.

Hahaha! Sod getting hit by a .500 bullet, I’ve fired a few rounds through a .505 Gibbs and the hit on my shoulder was enough alone!

 

[NigelM]

That is interesting...I guess the "double the mass double the energy, double the velocity quadruple the energy" principal applies.

But as you said earlier it is not black and white. Placement seems to trump all.

The "what works on a Roe will not necessarily work on a red" point though I am intrigued by in this context. Given we are always reading on here that .243W is enough for any deer in the UK...

I have been working up a load of 110gr TTSX in .308 W and they are travelling at 3200fps-is. Is there any reason they would not be as effective TV-wise as a smaller calibre similar weight bullet travelling at a similar speed on larger quarry than Roe? I was comparing the relative speeds of 100/120gr 6.5mm Creedmore TTSX which presumably are not restricted to Roe? I realise the BC and longer range advantages/differences.

I had been thinking they would work well for my Roe, Fallow and Muntjac at <150metres.

Alan

You're quite right, placement does trump everything. Plenty of elephants shot in the day with a 7x57 with perfect shot placement.

As for weight, I would be very happy shooting Roe with 80g but I wouldn't take them out on the Reds, I prefer 130 grain plus for that job. It allows for imperfect shot placement.

My take on Hydraulic shock is that we are not talking about bang flops caused by neck, solar plexus or heart shots, we are talking about the shock wave of the bullet causing severe damage to the neural system without hitting any vitals.

I'm sure your 110g TTSX would work on Reds - plenty on here will swear that a 100 grain 243 will be as good as anything else so why wouldn't a 110g 264 work.

It's not a black and white subject, it's about minimising risk.

After 20 years of experimenting with different chamberings from .243 to .308, different bullets from BT's through soft point and bonded to monolithic and different velocities from heavy at 2600 fps to light at 3400 fps I have settled on high BC bonded bullets at 2800 fps, 129g 6.5mm for Fallow and below and 150g 7mm for Sika and Red. If I was allowed to use my 22BR on Roe with the 69gr bullets I would, but I'm not. I don't look for Hydraulic shock anymore, I want a reliable kill with plenty of margin for error and acceptable carcass damage.

The subject is so complex that different people will draw different conclusions after trying out all the variables.

 

[Alantoo]

You're quite right, placement does trump everything. Plenty of elephants shot in the day with a 7x57 with perfect shot placement.

As for weight, I would be very happy shooting Roe with 80g but I wouldn't take them out on the Reds, I prefer 130 grain plus for that job. It allows for imperfect shot placement.

My take on Hydraulic shock is that we are not talking about bang flops caused by neck, solar plexus or heart shots, we are talking about the shock wave of the bullet causing severe damage to the neural system without hitting any vitals.

I'm sure your 110g TTSX would work on Reds - plenty on here will swear that a 100 grain 243 will be as good as anything else so why wouldn't a 110g 264 work.

It's not a black and white subject, it's about minimising risk.

After 20 years of experimenting with different chamberings from .243 to .308, different bullets from BT's through soft point and bonded to monolithic and different velocities from heavy at 2600 fps to light at 3400 fps I have settled on high BC bonded bullets at 2800 fps, 129g 6.5mm for Fallow and below and 150g 7mm for Sika and Red. If I was allowed to use my 22BR on Roe with the 69gr bullets I would, but I'm not. I don't look for Hydraulic shock anymore, I want a reliable kill with plenty of margin for error and acceptable carcass damage.

The subject is so complex that different people will draw different conclusions after trying out all the variables.

Absolutely. I am sure that we are hugely influenced by the highly unscientific/unrepresentative circumstances of our best and worst experiences, and those can determine our "fast and light" or "slow and heavy" type prejudices...

Alan