Terminal Ballistics

[Dalua]

Mr. Tahr's theoretical conviction that 150gr at 2000fps does not kill as well the same pill at 3000fps might be better explained in terms of greater expansion of the bullet, and therefore a bigger hole through the deer. On the other hand, with a bullet not designed for such an impact speed, the result might be quite otherwise.

Hi Dalua

Are you saying that providing both bullets expand to the same diameter and in doing so causes the same size wound channel, velocity plays no part in the terminal effectiveness of a projectile?

Best rgds

Tahr

I think what I'm saying is that the faster bullet would not have a better terminal effect because of anything other than its creation of a larger wound channel.
This might be because the faster bullet expanded to a larger size, although in the odd circumstance that they expanded to the same size notwithstanding a 1000fps difference in velocity, I think it would be reasonable to suppose that there would be more disruption to tissue around the path taken by the bullet in the case of the faster bullet. Why wouldn't there be?

What no-one has yet claimed actually to have seen are the mysterious and fatal effects a long way from the bullet wound.

 

[Dalua]

Hi Dalua,

We are going to have to agree that we disagree.

I think you're certainly right. Not just yet, though!

Following a heart shot, rupturing of the alveoli is clear throughout the soft tissue – and distinct in patches, normally about the size of an old 50p piece.

I'm not a vet, but in humans an alveolus is about 0.3mm across. They are found only in the lungs, of course. Might the apparent lung damage be caused by bullet or secondary bone fragments, I wonder? It wouldn't take much in there to cause a 50p-sized area of lung to become discoloured with blood, I wouldn't have thought.

Throughout my professional and academic career I have learnt to trust the specialists - particularly the guys that write the text books! Generally they are better educated than the majority of the interested parties; they tend to have knowledge of their subject far in excess to the average person. Their work can be crossed referenced and thus challenged or confirmed by other specialists.

'Trust' is an odd word. I must say during my career I have learned if anything the exact opposite to you. I don't think that 'trust' of experts should be allowed to make us skew our interpretation of our observations to fit their beliefs.

I don't think anyone is debating that one, are they? It is presumably energy transfer from the bullet to the gel or animal tissue.

Then where does the energy go? What is it transferred to or transformed into?

It does the work of damaging the deer or gel, doesn't it?

Best regards

Dalua

 

[morena]

Dalua If you wish to see the results of a distant reaction in blood vessels to trauma eg shot to the head go to a sheep slaughter house and you will find ecchymosis or blood splash on the diaphragm, forequarters, heart and lungs. The more stressed the animals the worse it is.The exact cause not known but involves high blood pressure in the blood vessels or weak blood vessels or a combination of the two.

 

[Dalua]

That's more like it, Morena!

I've no experience of what goes on in a sheep slaughterhouse, but if the animal is permitted to drop with its body-weight after the shot, might that trauma to fore-quarters and thorax might have something to do with the post-mortem appearance?

I imagine that stress in the animal would cause its blood-pressure to go up which might as you say predispose towards worse blood-spotting, and I suppose the sudden brain-trauma might cause a spasm in the whole vasculature which might cause damage to weaker vessels.

I suspect that nevertheless this has little to do with 'hydrostatic shock' from the impact of the slaughterman's bullet to the brain.

Out of interest, what is the velocity of the bullet used?

Dalua

 

[caorach]

This has certainly been a most interesting discussion. I, of course, remain unconvinced that I've seen any modern quantative science to support claims of pressure waves killing deer. Should such evidence come to light then I suspect it will make most interesting reading and it will certainly offer a possible explaination for some of the happenings that stalkers occasionally report. My very limited experience currently requires no further explaination than the simple science that a big hole in the right place makes things dead in a hurry and in the past I have seen good science to support this.

That the passage of a bullet does indeed create some form of pressure or shock wave and a temporary cavity is, I suspect, beyond dispute and it is possible that science lacks the resources or, more likely, the will to either carry out or, perhaps, publish research on this topic.

I don't feel I have a lot more to add to the discussion as my knowledge of the subject matter is, at best, very limited but I will be most interested to see if significant hard science comes to light to support either position. I, of course, don't "believe" in either position, I merely hold an opinion based upon the science I have read and new evidence could require a revision of my current opinion on the state of the science. That is how science works and what makes life so interesting.

 

[Chops]

Folks,

Just some of the evidence freely available; please follow the links below:

http://arxiv.org/ftp/arxiv/papers/0803/0803.3051.pdf
http://arxiv.org/ftp/arxiv/papers/0803/0803.3053.pdf

Both papers from March 2008...

Dalua

It does the work of damaging the deer or gel, doesn't it?

I fear you have either underestimated the kinetic energy a bullet has or have not grasped how energy behaves. Please see the fundamental law of 'Conservation of Energy'. Understand this, compare it with Newton’s 3rd law and you will find that there is a pressure wave, and it does serious damage, it is commonly called hydrostatic shock and it confirms to the fundamental theories of physics.

To state it [the bullet] does ‘damage’ is pointless and wholly unrepresentative of the question - where does the energy go? Specifically where can it go? If a bullet entering a body does not leave the other side then it expends all of its energy (ref. Ballistic Tip example mentioned ealier). This creates a large pressure wave.

This theory HAS been proven - it is in one of the papers above, referenced from many sources and studies and not just guess work by some bloke with a Tikka and Leupold - the very same paper even takes into account all of the attempts to dismiss the pressure wave theories. The conclusion I think is the most telling to all interested in this subject... just in case you haven't read it yet...
[url]http://arxiv.org/ftp/arxiv/papers/0803/0803.3053.pdf
[/url]

There is nothing more I can add... either trust in the science or read the Daily Mail...

Cheers

Chops

ps

It wouldn't take much in there to cause a 50p-sized area of lung to become discoloured with blood, I wouldn't have thought

I agree - but the splinter of bone would have to be the size of an old 50p piece if your logic is correct! Please also note that 'bloody' as not implied! Patches to ruptured tissue that look like bruising, where the pink light tissue has darkened and is showing sign of haemorrhaging. In fact they look very similar to the damage done the human lung suffering from a pulmonary barotrauma like a pneumothorax, following a diving related incident.

 

[smullery]

And all "bullets" of the same weight/external dimensions are not equal in how they perform upon impact assuming all other variables are the same.

That's what bullet design is all about.

Only way to trully compare/confirm is to "shoot" bullets at the same rate on living flesh and then examine the result on the living flesh. Then shoot the same bullets at the rate the designer wants then compare.

Desired results vary between "purpose" and "performance".



Stan

 

[caorach]

Just some of the evidence freely available; please follow the links below:

To be fair this isn't science, this is an opinion piece which contributes to a little spat on a pre-print server written by someone with a PhD in atomic, molecular and optical physics. It ends with the following:

"Selecting a good self-defense load is
only a small part of surviving a gunfight.
You have to hit an attacker to hurt him,
and you need a good plan for surviving
until your hits take effect. Get good
training, practice regularly, learn to use
cover, and pray that you will never have
a lethal force encounter armed only with
a handgun."

I certainly don't recall seeing any peer reviewed science with a similar tone, nor any that suggested depending upon prayer.

Maybe the man is correct but I certainly haven't seen any science from him and his opinion certainly hasn't managed to change mine.

 

[Dalua]

We are going to have to agree that we disagree.

The time has nearly come, perhaps.

The juxtaposition of science and the Daily Mail is an interesting one: I read a good deal of one of them, hardly any of the other, and implicitly 'trust' neither. Having said which in certain cases they probably have a good deal more in common than many would imagine.

The idea that stuff written under the 'science' banner by people with PhDs is intrinsically more or less free of spin, hidden influence and general mischief-making than the material written to fill our Great British Redtops is in my opinion a fallacious one. One is perhaps safer with science stuff published in reputable peer-reviewed journals, but one has to be careful even of that.

My point about the bone splinter was meant to be that a very small nick in the lung might well bleed enough to cause a 50p-size area of discolouration.

It might also be well to note that a rifle-bullet through the chest does actually cause, amongst other difficulties, a pneumothorax; so perhaps a post-pneumothorax-like appearance is not such a surprise?

Vive Col. Fackler!
A bas les Drs. Courtney!

 

[Chops]

Caorach -

The scientific foundation for ballistic pressure
wave contributions to bullet effectiveness does
not suggest that the pressure wave is the only
contributor to incapacitation. The permanent
cavity also plays an important role. The
relative importance of these mechanisms is a
matter for additional research.
One should not be overly impressed by the
propensity for shallow penetrating loads to
produce larger pressure waves. Selection
criteria should first determine the required
penetration depth for the given risk
assessment and application, and only use
pressure wave magnitude as a selection
criterion for loads meeting minimum
penetration requirements.
Reliable expansion, penetration, feeding, and
functioning are all important aspects of load
testing and selection. We do not advocate
abandoning long-held aspects of the load
testing and selection process, but it seems
prudent to consider the pressure wave
magnitude along with other factors.

All of this is peer reviewed! All of this work is referenced! There are even comments on negative reviews from peer review panels!

Can you really say that none of the testing is relevant, or that it carries no validity?

To be fair this isn't science, this is an opinion piece which contributes to a little spat on a pre-print server written by someone with a PhD in atomic, molecular and optical physics. It ends with the following:

...and their qualifications and experience are a little convincing than a bloke with Tikka in a field.

About the Authors
Amy Courtney currently serves on the faculty of the United
States Military Academy at West Point. She earned a MS in
Biomedical Engineering from Harvard University and a PhD in
Medical Engineering and Medical Physics from a joint
Harvard/MIT program. She has taught Anatomy and
Physiology as well as Physics. She has served as a research
scientist at the Cleveland Clinic and Western Carolina
University, as well as on the Biomedical Engineering faculty of
The Ohio State University. Amy_Courtney@post.harvard.edu

Michael Courtney earned a PhD in experimental Physics from
the Massachusetts Institute of Technology. He has served as
the Director of the Forensic Science Program at Western
Carolina University and also been a Physics Professor,
teaching Physics, Statistics, and Forensic Science. Michael
and his wife, Amy, founded the Ballistics Testing Group in 2001
to study incapacitation ballistics and the reconstruction of
shooting events. Michael_Courtney@alum.mit.edu

 

[Dalua]

Can you really say that none of the testing is relevant, or that it carries no validity?

I think I can safely say that none of it is likely to change my choice of calibre and bullet for use in the field.

...and their qualifications and experience are a little convincing than a bloke with Tikka in a field.

I have a Sako, a Schmidt und Bender and a BSc(Hons). Does that give me greater credibility?

 

[Chops]

Dalua -

It might also be well to note that a rifle-bullet through the chest does actually cause, amongst other difficulties, a pneumothorax; so perhaps a post-pneumothorax-like appearance is not such a surprise?
It might also be well to note that a rifle-bullet through the chest does actually cause, amongst other difficulties, a pneumothorax; so perhaps a post-pneumothorax-like appearance is not such a surprise?

A pueumothorax created by a barotrauma shows significant differences than one caused by a puncture; there in normally no clean hole but multiple framented tares. This leads to a dark red brused appearance and not bright red centred hole. Likewise a pneumothorax created by a problem higher in the broncial system (eg expanded medialstinal emphysema) will show other issues like taking on a blue colouration in the area of the collapse.

... we digress...

Personally I think this subjest has run its course; I will always accept the science that is presented if it matches what I think is logical and that has been present with data to back it up... I think I have seen that.

It's up to you 8)

Cheers

Chops
PS A Sako always beats a Tikka! and a MEng always beats a BSc

 

[Dalua]

I knew it! MEng the Merciless!

 

[Chops]

 

[jingzy]

Thanks guys,

this thread has been informative, interesting, and also contained less personal abuse and profanities than I was somehow expecting. It has provided members with reference material that I certainly didn't know existed, and in particular has provided up to date papers (thanks Chops) that I am going to try to digest.

Well done to all the members that contributed, a worthwhile exercise.

Cheers,

J

PS, Carry on if you feel the need to.

 

[morena]

Dalua: As requested ....... Captive bolt is powered by a .22 rimfire long blank +/- 550 fp/s .32 centrefire bullet +/- 6--700 fp/s 9 mm captive bolt +/-1200 fp/s .... Frontal shot in centre of forehead.

When I was inspecting at the slaughter house it changed ownership and went from stunning and bleeding to bleeding only ( halal bisallah) The incidence of blood spotting in carcasses dropped to negligible numbers. The only difference being the shot.

Ultrasonic scanning is by reflected waves all be it at low power.

When a bullet passes into a deer and does not exit where has that kinetic energy gone and what effect does it have on the body? A closed system in effect.

Also over the years when I have had to shoot horses have noticed the larger the calibre the less prolonged muscular reaction after they have dropped until the very large 400s they go down and lie still. With the smaller calibres the heart will go on beating for a longer period.

 

[Dalua]

Interesting stuff, Morena.

I know nothing about slaughtering procedures; the one explanation (not than the one i don't believe in, of course) is that the shot and bled beasts (unlike the bled-only ones) fall under their body-weight after the shot, and thereby wallop themselves on the deck, casuing the observed trauma.

One explanation for quicker 'deadness' in the horses shot with the bigger calibres might simply be more complete disruption of the brain than with smaller calibres, leading to quicker shutdown of motor and life-supporting functions.

I think that bullets impart energy to deer, and that that energy is dissipated in doing physical damage both to itself and to the animal. If they don't loose all their energy in doing that work, they come out. If they do loose it all, they don't. The elastic nature of much of an animal would presumably harmlessly (or at worst, with bruising) absorb a good deal of transmitted energy.

I think I'm running out of things to say about this. I wonder if that will stop me?

 

[Mac2]

I am sure you folk have seen this before, but it might help illustrate some of the very interesting points that have been made. While it is a promotional clip, it helps to demonstrate what happens on impact!



Mac