Hydrostatic Shock

NigelM

Well-Known Member
I have read a lot about Hydrostatic shock but have never experienced it.

Reading research on sites like Nathan Fosters Terminal Ballistics the consensus seems to be that Hydrostatic Shock starts to take effect from terminal velocities of 2600 fps and upwards.

My MV is 2970 fps so I have shot a lot of deer of all species with a terminal velocity of 2600 to 2850 fps using a Nosler 120 BT. Most are chest shot, but none of them drop on the spot, I always get the classic back legs kicked in the air and take off 20 to 60 yds before falling over.

Is it the speed or is it the fact that I'm using a fragmenting bullet?

I have shot plenty of foxes in the chest which have dropped on the spot, probably from Hydrostatic Shock, using a 70 grain bullet at 3600 fps. But how fast does a bullet really need to be going to get the instant drop on the different species of deer from a chest shot?

It would be very interesting to hear from SD members on the subject.

1. How often have you experienced it?
2. What species were you shooting?
3. What terminal velocity was the bullet running at?
4. What type of bullet were you using?

With all the experience on this site we might even get some valuable research out of it.
 
I'm not convinced it is a true phenomenon. How can you distinguish between true physical trauma/shock and hydro-static? There are so many factors that determine whether or not a deer drops on the spot or runs and none of them are truly quantifiable. Size of deer, species of deer, range, calibre, bullet speed, bullet weight, alertness of animal, etc..
Sometimes a big animal will drop with a lung shot and sometimes a small animal will run 100m with a tennis ball size exit wound where its heart once was!
You can read all the research you like, but deer can't read and they might not comply!
MS
 
You can read all the research you like, but deer can't read and they might not comply!

...Sika must be particularly dyslexic
 
Your experience seems to support what I believe to be true - namely that 'hydrostatic shock' (assuming it exists at all outside the minds of some terminal-ballistics pundits) is not something that can be relied upon in the field over making an adequate hole through the right part of the animal.

I like this essay on the subject: http://www.rathcoombe.net/sci-tech/ballistics/myths.html#energy
others have different views!

:)
 
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The funny thing is in my experience, the smaller and faster the calibre, the faster they drop. .222 on roe = drt, 6.5-30cal = hope you brought the dog
 
I have seen many dramatic kills over the years. The most consistent rounds used to obtain deer that drop in their own footprints are the Barnes 130g TTSX in 308 and the Hornady 162SST in 7mm RM. I have shot lots of other bullets, particularly in 308 but have found no others as consistent. I put this down to rapid expansion with huge temporary cavitation with the TTSX and the bullet coming unglued and causing massive tissue trauma with the SST
 
Only shot a few Sika with 22-250 52gr, they dropped just like foxes. Like others I would not want to rely on hydrostatic shock alone, not push my luck and therefore rather us a different calibre. Funny thing is I didn't get such kills with a 243/80gr 3100fps with similar H/L shot placement.
edi
 
As a counter thought, how about the reliable and quick killing of cartridges which are launched about 2,450 to 2,600 fps, like the old 6.5x55, the 140-gr 7x57, the .30-30, the 180-gr RN from the .303 Enfield or the .300 Savage, the 117-gr .257 Roberts, or even the 6.5x54 Mannlicher?

These bullets don't give up energy in disintegration; they expand, stay together, travel in a straight line, and exit. And deer fall over.
 
I think Dropping them on the spot is about bullet placement, with 110 bt 270 rounds, the shock is where did the head go.
 
As a counter thought, how about the reliable and quick killing of cartridges which are launched about 2,450 to 2,600 fps, like the old 6.5x55, the 140-gr 7x57, the .30-30, the 180-gr RN from the .303 Enfield or the .300 Savage, the 117-gr .257 Roberts, or even the 6.5x54 Mannlicher?

These bullets don't give up energy in disintegration; they expand, stay together, travel in a straight line, and exit. And deer fall over.

Do they though? I have a .280AI which delivers 140 grain Barnes TSX bullets with phenomenal accuracy. They always exit and the deer is effectively dead, but they don't half run! Meat damage is minimal compared to my 25.06 with BT's which generally drops deer much better. There is no nemesis here. Trauma = knock-down = meat damage. A small frangible bullet at high speed and close range will knock an animal over better than a heavy low speed one at longer range. Both animals will die, but one might take longer to find and will have less meat damage.
MS
 
I was extremely lucky tonight to get 4 deer, 3 fallow, 1 roe doe, the roe and the largest fallow buck dropped like a stone, yet both fallow does ran 40 ish Yds. All were shot with a .243, using Sierra 1560, 100 Grn Gameking @ a measured average Mv of 2810 Fps. The roe and Fallow Buck were within 100 Yds, the 2 Fallow does @ approx 150 Yds, so clearly the lower terminal velocity might account for that.

All Fallow shot were broadside chest shots, the Roe was quartering away, so was engine room exiting front quarter. The Fallow buck was mashed heart lung internals, whereas the FD's were all heart lung but not smashed, just holed. All were dead quickly, so I suspect its just about imparted energy, if the bullet opens enough and dumps that energy and this will be governed by terminal velocity/range. I suspect caliber has little to do with it?
 
Do they though? I have a .280AI which delivers 140 grain Barnes TSX bullets with phenomenal accuracy. They always exit and the deer is effectively dead, but they don't half run! Meat damage is minimal compared to my 25.06 with BT's which generally drops deer much better. There is no nemesis here. Trauma = knock-down = meat damage. A small frangible bullet at high speed and close range will knock an animal over better than a heavy low speed one at longer range. Both animals will die, but one might take longer to find and will have less meat damage.
MS
Do they? 100 years of experience with these cartridges is that, yes, they do kill reliably.

I think the keys are:
A. Hitting game when it is not frightened and full of adrenaline
B. Shot placement and angle to get the right organs, break bones, damage spine
C. Matching the rifle and bullet and impact velocity to the game.

A 180-gr .303 bullet launched at 2,400 fps and hitting a deer 300 yards out perfectly, but only going 1800 fps, may not open up, may just drill a hole. Then again, it may knock the deer off its feet.

A .25-06 bullet hitting a deer at 300 yards is like a .257 Roberts hitting it at 200 yards... same result.

A .280 or 7x64 bullet hitting anything at 300 yards is like hitting it with the same bullet from a 7x57 or 7mm-08 at 200 yards.

The .270 is a deer killer, but meat damaging inside 200 yards with 130-gr bullets, still going over 2,700 fps. Load a 150-gr bullet at 2,900 fps, and it will do less destruction at closer range, but shoot through and drop red deer, elk, big boars and bears out to 300 yards, ( and deer, but that is where the 130 or 140 is better on lighter-skinned game).
 
I have seen many dramatic kills over the years. The most consistent rounds used to obtain deer that drop in their own footprints are the Barnes 130g TTSX in 308 and the Hornady 162SST in 7mm RM. I have shot lots of other bullets, particularly in 308 but have found no others as consistent. I put this down to rapid expansion with huge temporary cavitation with the TTSX and the bullet coming unglued and causing massive tissue trauma with the SST

Hi srvet.

Being a Vet do you suspect the large temporary cavity results in what I can only describe as a 'pressure spike' in the Blood supply to the Brain leading to unconsciousness? The Animal Dying of its Wounds whilst Unconscious?
I have read of this theory relating to high velocity bullets but never read a Veterinary Qualified opinion of it.
Thanks.

Yorkie.
 
Maybe we should be considering a mix of Hydro & Pneumo - static shock. No joke!

Hydro = water (blood & other fluids in the case of shooting quary) -- water is incompressible hence the shock effect & damage is relatively great.
Pneumo = air (lung contents) -- air is easily compressable & the shock effect is less.

Guess why you have not seen much evidence of hydrostatic shock with a chest shot....... -- You're mostly shooting through air.
Only if you hit forward & hit the heart/arterial major blood system will you possibly get the hydro bit.

The size (volume) of the target (deer compared to fox) means that the same bullet hitting the same area of the animal will have greater effect on the smaller beast. Hence charlie goes down & expires quicker than bambi.
The extent of shock is often seen when killing foxes - bullet sized input hole & a fist sized hole on the exit being quite common - On deer the large fist sized exit wound is rarely seen. The shock is proportionally larger on the smaller beast leaving proportionally greater damage & knock down effect.

Maybe a pathologist could put a better explanation forward, but one I spoke to recently spoke more about bleeding causing death than anything else.
Velocity was not in his view the critical factor. He, after doing many years of research is of the opinion that as long as your bullet is going above the velocity needed to initiate expansion it's velocity doesn't make so much difference & that bullet size was not important with soft tissue strikes (within sensible limits - of course). WARNING-- CAN OF WORMS No.1!!! LOL.

You cannot expect any bullet fired at reasonable velocity to flatten a deer if it strikes the soft tissue area - Instant collapse is only guaranteed by smashing bone & preferably nerves (head / spine / shoulders) CAN OF WORMS No.2!!! - Head & Spine = BAD PRACTICE IMHO . Neck marginal practice - only to be done by very experienced people.

Fragmenting bullets on deer???? CAN OF WORMS No.3!!!

Have fun with your research & remember not to compare too many apples with pears.

Ian
 
do you suspect the large temporary cavity results in what I can only describe as a 'pressure spike' in the Blood supply to the Brain leading to unconsciousness?

I'm not a vet, but I am aware that the cardiovascular systems of mammals are plumbed with more-or-less elastic pipes. If what is referred to here is something like the wound to the chest being the brake-pedal and the brain the hydraulic piston at the brake-disc, then I can't help but think the idea implausible. Think of the brake-pipes on your car replaced with rubber tubing.

Hydro = water (blood & other fluids in the case of shooting quary) -- water is incompressible hence the shock effect & damage is relatively great.
As I said - blood and tissue fluids are contained in more-or-less elastic vessels of one sort or another. The 'give' in those tissues would, I imagine, do much relatively harmlessly to absorb and dissipate a local compression; rather than pass it down the column of fluid, as in a hydraulic brake system. So the imcompressability of the water seems to me a concept not directly relevant.

As to setting up actual 'shock waves' in blood, would this not require a genuine explosive-type shock, where the wave moves faster than the speed of sound in that medium. I think the speed of sound in water is about 5000fps.

Would probably be illegal to use in the UK on game on the technicality that they are not designed to expand and so would be in contravention of the deer act!
Does its hollow point not mean that it would be perfectly lawful to use on deer in England and Wales? Only Scotland AFAIK mentions expansion in the criteria - and of course both rules apply only to deer.
 
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I did have a photo on my phone until recently that a mate and I wondered if it was showing sign of static shock.there was area approximately 6 to 7 inch circle where the pins had been shocked. Not sure how to describe it.had 2 the same that day.200yds with the 308 using 155gr amax.this was the acid test for me after all the things that were said about them but after reading on terminal ballistics I would try them.mv of 2933fps if an thing they expand more than most other bullets I've tried.have not used them since.i would of said they were dead before they hit the floor
 
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I did have a photo on my phone until recently that a mate and I wondered if it was showing sign of static shock.there was area approximately 6 to 7 inch circle where the pins had been shocked.

Maybe it had heard its father's ghost?
[FONT=Arial, Arial, Helvetica]..Thy knotted and combined locks to part
And each particular hair to stand on end,
Like quills upon the fretful porpentine:[/FONT]


Or had you perhaps rubbed the bullet on a nylon carpet before loading? That might have given it a bit of a jolt.
;)
 
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