How bullets Kill

Thanks, that's quite an interesting read. I'm quite interested in the physiological effects of bullets. Especially the 'shock wave' element of it.
 
This might be an interesting link to have a look at for all deer stalkers. Quite often people post videos, and the deer runs after a perfect shot. I have tried to answer this question in the past and had mixed reactions , so here is the link.

Gary

http://bogveidi.net/index.php/fraedhigreinar/132-ahrif-a-qshock-effect-a-dyrq

SNH use a guy who was a forensic scientist for the scottish police force knows all the bits and pieces ,that shows the full thing from leaving the end of the barrel to hitting ballistic gel wound channels for different types of ammo etc interesting for those that have a interest in more than just pulling the trigger ,and hoping the beast will fall over .
 
I was refering to this in another thread the other day. It is the first time I have read that extract and notice that the stuff I have previously read was in the references at the bottom. The knock out effect is very interesting where it is believed to be a massive rush of blood to the head that knocks the animal out.
 
I was refering to this in another thread the other day. It is the first time I have read that extract and notice that the stuff I have previously read was in the references at the bottom. The knock out effect is very interesting where it is believed to be a massive rush of blood to the head that knocks the animal out.

Surely it is the sudden loss of blood pressure that causes unconsciousness.
 
if someone clocks you with a haymaker on the chin and catches your vagus nerve you will drop on the spot!

Why would a bullet passing within 6" of the spine be any different?

Shock is a killer as well as a force powerful enough to incapacitate through CNS disruption
I don't buy the massive rush of blood to the head or loss of blood causing instant unconsciousness
 
if someone clocks you with a haymaker on the chin and catches your vagus nerve you will drop on the spot!

Why would a bullet passing within 6" of the spine be any different?

Shock is a killer as well as a force powerful enough to incapacitate through CNS disruption
I don't buy the massive rush of blood to the head or loss of blood causing instant unconsciousness

So in either scenario would you be unconscious or incapacitated.
 
depends on the bullet and placement. if it's a calibre and bullet construction + speed that creates a lot of shock via a very large temporary wound tract, chances are a small deer will die instantly of shock as long as it penetrates to the vitals...likewise, if that bullet is a solid barnes that passes through with a smaller wound tract, chances are it might run and die from blood loss.

a head shot will kill it instantly no matter what if placed right, so 'may' a neck shot in many cases, and a spine shot is more likely to leave it conscious but immobile whilst it bleeds out having taken the top of the lungs out.

but these things change from time to time, you can shoot a roe with a barnes solid with a big slow calibre and have it go straight down dead on the spot,,did it die from blood loss or shock?...maybe shock,,had it been a .223 with a 60g partition, it might have passed through swiftly and died from blood loss since it's such a light bullet and not potentially expanding to create the shock effect, in that case, probably blood loss with a 'bit' of shock due to the speed of the .223.

I suppose if my theory is correct, which it probably is not, then the worst thing is a middle of the road calibre with a slow-ish moving high integrity bullet...therefore, a 6.5x47L or 6.5x55 with a 120g to 140 barnes triple shock should be the worst thing you can use as it does not have high speed explosive impacts nor big heavy OOOMPH impacts....but,,they 'do' knock deer over dead,,which leaves us nowhere!
 
Shabz link above is far more authoritative, and less confusing.

There is a lot of confusion about terminology and definitions here, as well as the physiological causes of death.

Medical Shock = blood loss or loss of pump action (heart) -----> loss of blood pressure -----> death ultimately due to no perfusion and no oxygen reaching the organs unless shock halted and reversed before the point of no return. This is caused by the bullet's physical wound channel through large vessels or the heart usually, in which case it will be a rapid process. Hit smaller vessels or blood-laden organs such as spleen or liver----> slower onset of shock and death.

Hit CNS with bullet - usually instant brain death and motor collapse, followed by cardio respiratory death due to loss of neural drive of respiration.

No man or no animal ever died from the "shock" of the sound wave of a bullet.

The pressure wave of impact and passage through the target causes a large elastic and temporary wound channel in addition to the physical wound channel bored out by the bullet itself.
 
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No man or no animal ever died from the "shock" of the sound wave of a bullet.

nobody mentioned "sound" but I have first hand experience of several animals dying at my hands from exactly that

1) Fox. Headshot with a .22lr CB long at 25 feet. drops in its footprints.
on closer examination the bullet had barely penetrated the skin let alone the skull. no blood loss at all. I skinned the head to examine it and the skull was not visibly fractured at all but on splitting it the frontal lobe was completely obscured by a subdural haematoma
Only the transfer of kinetic energy can have caused its death. no physical wound tract or blood loss at all.

2) several examples of neck shot stags where the bullet missed the spine.
one exposed the spine but did not chip or fracture it.
totally stone dead on arrival at the animal (90yd walk)
No significant blood loss, no vital organs destroyed.
blunt trauma, kinetic energy, impact shock




"The other popular contemporary misconception results from the belief that the rapid "transfer" of the kinetic energy of the bullet thereby kills instantaneously through "hydrostatic shock".
I don't know where this term originated, but it is pseudoscientific slang. Shock, in the technical sense, indicates a mechanical wave travelling in excess of the inherent sound speed of the material. This may be a flow related wave like a bow shock on the nose of a bullet in air or it may be a supersonic acoustic wave travelling through a solid. In terms of bullets striking tissue, shock is never encountered."
The sound speed of muscle tissue has been measured to be about 5150 fps, and that of fatty tissue around 4920 fps Even varmint bullets do not have an impact velocity this high, let alone a penetration velocity exceeding 4900 fps. Unless the bullet can penetrate faster than the inherent sound speed of the medium through which it is passing, you will not observe a shock wave. Instead, the bullet impact produces an acoustic wave which moves ahead of the penetration"


He loses my attention after the last statement
"Sound" is nothing more than a mechanical wave within a certain frequency range.

tell that to this donkey:

 
Unless the bullet can penetrate faster than the inherent sound speed of the medium through which it is passing, you will not observe a shock wave.

There will always be a hydraulic (if defined as 'shock' wave] action on liquids; it's physics, you cannot compress a liquid, which is how hydraulics and robots work for example. For a live target that will include blood supply and similar.
The energy that is transferred in a bullet impact is kinetic and acoustic and thermal; not mutually exclusive. If you could cherry pick the energies, BAe Systems would have done it a long time ago.
 
1) Fox. Headshot with a .22lr CB long at 25 feet. drops in its footprints.
on closer examination the bullet had barely penetrated the skin let alone the skull. no blood loss at all. I skinned the head to examine it and the skull was not visibly fractured at all but on splitting it the frontal lobe was completely obscured by a subdural haematoma
Only the transfer of kinetic energy can have caused its death. no physical wound tract or blood loss at all.

2) several examples of neck shot stags where the bullet missed the spine.
one exposed the spine but did not chip or fracture it.
totally stone dead on arrival at the animal (90yd walk)
No significant blood loss, no vital organs destroyed.
blunt trauma, kinetic energy, impact shock

Pressure wave trauma in the inelastic brain causing brain death.
 
Pressure wave trauma in the inelastic brain causing brain death.

agreed on the pressure wave
Brain is much more elastic than the spinal cord. nothing reacts well to blunt trauma....shock

and what is pressure if not the result of kinetic energy applied to a body?
If delivered quickly it comes as a "shock"

they both looked pretty fecking shocked!
 
1) Fox. Headshot with a .22lr CB long at 25 feet. drops in its footprints.
on closer examination the bullet had barely penetrated the skin let alone the skull. no blood loss at all. I skinned the head to examine it and the skull was not visibly fractured at all but on splitting it the frontal lobe was completely obscured by a subdural haematoma
Only the transfer of kinetic energy can have caused its death. no physical wound tract or blood loss at all.
The idea that a knock on the head can kill is surely neither novel nor surprising? It is perhaps not that 'transfer of kinetic energy' that has caused this death, but the physical damage occasioned by the energy transferred.

2) several examples of neck shot stags where the bullet missed the spine.
one exposed the spine but did not chip or fracture it.
totally stone dead on arrival at the animal (90yd walk)
No significant blood loss, no vital organs destroyed.
blunt trauma, kinetic energy, impact shock

I suspect that if a bullet has inflicted damage close enough to the spine to expose it, it seems not unlikely that the spinal cord will have traumatised also.
One might particularly imagine this to be the case if the beast goes down like a sack of spuds and then dies. The central nervous system is a 'vital organ'.






"The other popular contemporary misconception results from the belief that the rapid "transfer" of the kinetic energy of the bullet thereby kills instantaneously through "hydrostatic shock".
I don't know where this term originated, but it is pseudoscientific slang. Shock, in the technical sense, indicates a mechanical wave travelling in excess of the inherent sound speed of the material. This may be a flow related wave like a bow shock on the nose of a bullet in air or it may be a supersonic acoustic wave travelling through a solid. In terms of bullets striking tissue, shock is never encountered."
The sound speed of muscle tissue has been measured to be about 5150 fps, and that of fatty tissue around 4920 fps Even varmint bullets do not have an impact velocity this high, let alone a penetration velocity exceeding 4900 fps. Unless the bullet can penetrate faster than the inherent sound speed of the medium through which it is passing, you will not observe a shock wave. Instead, the bullet impact produces an acoustic wave which moves ahead of the penetration"


He loses my attention after the last statement
"Sound" is nothing more than a mechanical wave within a certain frequency range.
I'm not sure I know enough physics to understand what he's on about.
However, what he seems to be saying is that 'shock' involves pressure-waves travelling faster that the speed of sound in a given medium. He then makes the point that bullets do not enter tissue faster than the speed of sound in those media, and that therefore whatever pressure-waves are set up, they cannot be in this technical sense 'shock'. They must therefore be something else, and that something is acoustic waves.
By all means let me know what you make of his statement - as I say, I'm no physicist so be gentle!



tell that to this donkey:



I'm not sure what the vid demonstrates - I can't tell where the beast was hit. It is interesting to note that the poor bugger is trying manfully to stand up again at 14-15seconds.
 
I was once shot full in the cheek by one pellet of no 6 shot at about 30x range, so travelling at say 600mph. I have a clear recollection of 2 separate but sequential sensations. The first was the pellet passing through skin and cheek like a knife through butter, without pain or resistance to it's progress. The second was a really hard blow similar to a very good punch indeed when it hit my tooth, on the gum line. This was " shock", in the non technical sense, but how much more it would have been with a bullet. Of course there was no comparison at all, but from this experience, I would have expected a bullet strike to deliver a knock out punch, irrespective of damage to organs, but in fact deer can look remarkably unaffected even by a fatal blow. I wonder if any soldiers with real experience of being shot can throw light on the issue.
 
The idea that a knock on the head can kill is surely neither novel nor surprising? It is perhaps not that 'transfer of kinetic energy' that has caused this death, but the physical damage occasioned by the energy transferred.

Absolutely. but not through the usual method when there is no hole.
Energy transfer through a shock/pressure wave.
Exactly the opposite to the authors theory that
"The other popular contemporary misconception results from the belief that the rapid "transfer" of the kinetic energy of the bullet thereby kills instantaneously through "hydrostatic shock".


I suspect that if a bullet has inflicted damage close enough to the spine to expose it, it seems not unlikely that the spinal cord will have traumatised also.
One might particularly imagine this to be the case if the beast goes down like a sack of spuds and then dies. The central nervous system is a 'vital organ'.

Again, it will have been absolutely traumatised, but not by the physical destruction planned but by a shock/pressure wave




I'm not sure I know enough physics to understand what he's on about.
However, what he seems to be saying is that 'shock' involves pressure-waves travelling faster that the speed of sound in a given medium. He then makes the point that bullets do not enter tissue faster than the speed of sound in those media, and that therefore whatever pressure-waves are set up, they cannot be in this technical sense 'shock'. They must therefore be something else, and that something is acoustic waves.
By all means let me know what you make of his statement - as I say, I'm no physicist so be gentle!

That is his judgement, I have not come across it anywhere else that says shock must be faster than the speed of sound in a given media.
He brings "sound" into the equation when actually shock is just another description for a high velocity pressure wave.
(Sound is nothing more than a pressure wave in an audible range)
My point is that people go out of their way to say that a shock wave, pressure wave, hydrostatic shock or whatever you want to describe it as can not kill.

I say it can and does.
Death without blood loss or physical destruction of vital organs has to come from energy transfer through the tissues themselves. A shock wave.
It even works on submarines!

Some people even say it does not exist.


I'm not sure what the vid demonstrates -

What it demonstrates is that poor Donkey's body is hit with a pressure wave strong enough to blow the mud off it's coat!!
Fatally hit or not, a 375H&H is going to impart a great deal of energy on a solid body, if that body is mostly liquid it will and does pass through in a huge wave radiating out from the point of impact and the wound channel as it goes.
it is clearly visible in the slow motion portion especially at 33 seconds



you don't need to be an engineer or physicist to see what is happening.
I am not sure why it raises so many questions or many papers are written trying to recalculate the mathematical explanation to prove it does not happen.
 
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you don't need to be an engineer or physicist to see what is happening.
Indeed not, but perhaps an understanding of engineering or physics (and perhaps anatomy and physiology) is neccessary to understand what is happening, and to be able to describe it accurately.

I don't think we're disagreeing about much: only two things, perhaps?
First, it seems to me correct to say that 'shock' is a technical term describing the propogation of energy in a medium at a speed higher than the speed of sound in that medium, and that 'acoustic' refers to a propogation at subsonic speeds in that medium. This suggests to me that your assertion 'shock is just another description for a high velocity pressure wave' might be an unhelpful oversimplification.
To summarise that bit, we can, or course, give whatever name we want to anything we like. We could call bullets 'heads', male red deer 'bucks', and so on: but on the whole we find that sticking to conventional and/or technically accurate names serves the purpose of clear communication best.
http://physics.info/shock/
So much for 'shock.'

The second thing is the idea of hydrostasis as having much to do with this. As you say, 'the body is mostly liquid'. However, the liquid is not like the liquid in a hydraulic circuit, or in a sealed vessel. The liquid is contained in and around highly elastic structures, both macro- and microscopic, which are apt to absorb energy up to a certain level without sustaining much damage.

So, your dead stag with the bullet-wound near his spine could well have had his cord traumatised, perhaps by temporary displacement, enough to cause death. I would argue that this has nothing to do with hydrostasis, and nothing to do with technical 'shock'.
The fox tapped on the head by the .22 bullet had evidence of local damage to the extent of a subdural haematoma, so none would doubt the source of the fatal blow - but no-one would dispute that a bang on the head can kill: however, this is not to do with hydrostasis or 'shock' either.

To summarise, it seems to me that the transfer of kinetic energy that causes problems for our quarry is not accurately described as 'shock', whether 'hydrostatic' or otherwise.
 
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First, it seems to me correct to say that 'shock' is a technical term describing the propogation of energy in a medium at a speed higher than the speed of sound in that medium, and that 'acoustic' refers to a propogation at subsonic speeds in that medium.

http://physics.info/shock/


Ah now I see the issue.
The author of that first article and the description in the link above are not detailing the shock wave when two solids (or dense liquids) impact (mechanical shock).
The article is very specifically explaining the principle of a "sonic boom" and the resultant shock wave as an object accelerates through its own pressure front in a medium presents resistance (in this case air).
by definition breaking the sound barrier (in air) results in a pressure wave travelling at or above the speed of sound.
Extrapolating that into solids is not relevant in this example.

This is mechanical shock- defined (simply) as:
“a non-periodic excitation of a mechanical system, that is characterized by suddenness and severity, and usually causes significant relative
displacements in a system.”
Shock is a transient physical excitation simply measured by accelerometers
You can plot shock on a graph, acceleration over time
A drop, an impact, a collision etc
The key element is the short time frame of the acceleration


some light reading: http://www.pcb.com/techsupport/docs/vib/lores_24__mechanical_shock_tech.pdf

To summarise, it seems to me that the transfer of kinetic energy that causes problems for our quarry is not accurately described as 'shock', whether 'hydrostatic' or otherwise.

I totally agree it is all about energy transfer, as I did above.
Couldn't care less what people call it but "shock" it definitely is. Purely on the basis of its delivery. sudden and severe
I agree using any term relating to hydrostasis/hydrostatic is misleading, but as you say, people call them "bullet heads" and we still know what they mean

From a physiological point of view (and that is a field where I am more comfortable) shock (or in simple terms very fast acceleration and/or deceleration) in tissue is enough to create significant injury and kill.

The fox shot in the head at low velocity has caused by the brain to slam against the inside of the skull as the skull accelerates in the opposite direction. A certain amount of elasticity in the frontal plate exacerbates this.
Brain injuries quite often display damage on the opposite side of the skull due to the secondary impact as the skull stops but the brain continues. (Rattle a ball in a bottle for an analogy)
A subdural and more likely, epidural haematoma may simply raise the intracranial pressure to a fatal level, very quickly

The death of a stag shot through the back of the neck but missing the spine is caused by the permanent disruption of the autonomic pathways of the spinal cord. no physical disruption, break, or CSF burst is necessary. just a shock wave.
The autonomic pathways are the unconscious control pathways, including heart and respiratory rate,
Neurogenic shock in car crash victims is well documented
 
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