Energy to kill a coyote

Quote:A bullet kills by hydrostatic shock, a pressure wave caused by the transfer of energy.

Negative sir. I know that's been a popular theory seemingly forever (or at least since I was a a boy which is close to forever), but it's an absolutely incorrect theory.

There has been way too much research done on terminal ballistics for "hydrostatic shock" to even be considered. Popular {mis}conception just hasn't caught up with reality yet.

Think of it this way, if hydrostatic shock was the killing force, Ir wouldn't matter where your bullet hit the target. A hit anywhere would kill because of that "pressure wave". That {obviously} is not the case.
 
Originally Posted By: nmleonQuote:A bullet kills by hydrostatic shock, a pressure wave caused by the transfer of energy.

Negative sir. I know that's been a popular theory seemingly forever (or at least since I was a a boy which is close to forever), but it's an absolutely incorrect theory.

There has been way too much research done on terminal ballistics for "hydrostatic shock" to even be considered. Popular {mis}conception just hasn't caught up with reality yet.

Think of it this way, if hydrostatic shock was the killing force, Ir wouldn't matter where your bullet hit the target. A hit anywhere would kill because of that "pressure wave". That {obviously} is not the case.

You were compairing apples and oranges.
Than you and I will disagree. You don't need to go through both lungs to colapse both. You need both shot placement and energy to kill. Most of the research that has been done, has been with military non expanding rounds. Those rounds don't expand and transfer energy the same way hunting rounds do. You site no research.
That is why most States do not allow non expanding military style rounds to hunt big game. This is from the Illinois hunting regs. for hunting with handguns.
Quote:  For handguns, a bottleneck centerfire cartridge
of .30 caliber or larger with a case length not exceeding
1.4 inches, or a straight-walled centerfire
cartridge of .30 caliber or larger, both of
which must be available as a factory load with
the published ballistic tables of the manufacturer
showing a capability of at least 500 foot pounds
of energy at the muzzle. Note:There is no case
length limit for straight-walled cartridges.
 Non-expanding, military-style full metal jacket
bullets cannot be used to harvest white-tailed
deer; only soft point or expanding bullets (including
copper/ copper-alloy rounds designed
for hunting) are legal ammunition

As you can see, they believe there is a difference. If you shoot a fox with too much gun, you have a small entry wound. And a fist sized exit wound. The bullet doesn't expand that much, usually doubles in size. Or just watch video of a bullet going through ballistic gel. You can see an expanded wound channel. If there is research on hunting rounds I would really like to read it. If it was all about shot placement than everyone could hunt with a .22LR.
 
You need enough energy to cause proper penetration of the bullet type used and enough energy to cause the bullet to perform as designed (fragment, expand/mushroom, etc.).

That has absolutely nothing to do with "hydrostatic shock, a pressure wave caused by the transfer of energy". The only place that has any validity is (possibly) with a shot to the liver (basically a loose/fragile bag of blood).

You are right though, I didn't cite any research. I apologize. Try the link below. That one should be all you need to start you on the road to enlightenment. If you are still curious when finished, do a search for some of the references at the end of it.

By the way, M.L. Fackler, M.D. is actually Colonel M.L. Fackler, M.D., the Director of the Letterman Army Institute of Research, Division of Military Trauma Research, Presidio of San Francisco.

He headed complete ballistics and forensic labs, had the doctors, physicists, and ballistics engineers to staff them, and the budget to fund the research. His teams spent many years studying not only human corpses (autopsies) and animal carcasses (necropsies) but ballistic gelatin and what nobody else had ever done, high speed x-rays of living animal flesh as bullets were damaging it. While their focus was military, they studied a wide variety of different types of projectiles from spherical to fragmenting to FMJ to VLD, etc.

In the paper below (only one of many) he also addresses some of the consequences of the common misconceptions about wound (terminal) ballistics, which has not only included poor weapons design parameters, but also (obviously) the State of Illinois' hunting regs.

http://rkba.org/research/fackler/wrong.html

Attempts to explain wound ballistics (the study of effects on the body produced by penetrating projectiles) have succeeded in mystifying it. Fallacious research by those with little grasp of the fundamentals has been perpetuated by editors, reviewers, and other investigators with no better grasp of the subject. This report explains the projectile-tissue interaction and presents data showing the location of tissue disrupted by various projectiles. These tissue disruption data are presented in the form of wound profiles. The major misconceptions perpetuated in the field are listed, analyzed, and their errors exposed using wound profiles and other known data. The more serious consequences of these misconceptions are discussed. Failure in adhering to the basic precepts of scientific method is the common denominator in all of the listed misconceptions....

MAJOR MISCONCEPTIONS
1. Idolatry of Velocity:...
2. Exaggeration of Temporary Cavity Size, Pressure, and Effect:....
3. Assumption of Bullet "Tumbling" in Flight:....
4. Presumption of "Kinetic Energy Deposit" to Be a Mechanism of Wounding:....
Many body tissues (muscle, skin, bowel wall, lung) are soft and flexible--the physical characteristics of a good shock absorber. Drop a raw egg onto a cement floor from a height of 2 m; then drop a rubber ball of the same mass from the same height. The kinetic energy exchange in both dropped objects was the same at the moment of impact. Compare the difference in effect; the egg breaks while the ball rebounds undamaged. Most living animal soft tissue has a consistency much closer to that of the rubber ball than to that of the brittle egg shell. This simple experiment demonstrates the fallacy in the common assumption that all kinetic energy "deposited" in the body does damage....
 
It will take some time to read all of that. I think I have read parts of that before. Dr Fackler made a lot of his observations while a surgeon for the army in Viet Nam. That report was published in 1987. The link below is one from a West Point study in 2007. On the effects of "Ballistic Preasure" without a wound channel. Here is the conclusion.

Quote: IV. Discussion and Conclusion
In conclusion, the direct observation of
incapacitation by ballistic pressure wave apart
from permanent crush cavity and temporary
stretch cavity effects strongly supports the
validity of the pressure wave hypothesis, as
well as the independence of pressure wave
and wound channel contributions inferred from
analysis of the Marshall and Sanow data set
[COC06b].
While the experiment described here provides
compelling evidence for the incapacitation
effects of a sufficiently large ballistic pressure
wave, this work is primarily a qualitative
demonstration. This experimental method
should not be interpreted as a recipe for
evaluating the incapacitation potential of
individual handgun loads because the wound
channel also plays an important role in
incapacitation. A quantitative analysis of the
relative importance of the pressure wave and
wound channel as contributors to
incapacitation is presented elsewhere
[COC06b].


Ballistic Preasure Study
 
You might reread that. It's a study of an external ballistic pressure wave by a physicist (not a MD), and the conclusions are reached without determining the physical mechanism of incapacitation or death.

I can help there.
rolleyes.gif


I was a deep sea oil field diver for eight years, and did a fair amount of explosives work during that time, even working for a short time as an explosives engineer.

A diver who is submersed anywhere near a blast of any size is dead. Period.

That, according to Courtney's study, would be "compelling evidence for the incapacitation effects of a sufficiently large ballistic pressure wave".

True as far as it goes, but further examination would show that what killed the diver was the sudden compression of the "air spaces" (interstitial spaces) in his lungs, sinuses, etc, when the external pressure suddenly increased without allowing sufficient time for internal airspace equalization. From the description given, that is exactly what happened with Courtney's subject animals. It has absolutely nothing to do with projectile terminal ballistics.

If that same diver is standing on the ladder of the barge, only in the water up to his waist, he won't even feel the blast (pressure wave) in his legs. That's not theory, I have done it.

Is that evidence that a "large ballistic pressure wave" is harmless? By Courtney's methodology it might be.

Dr Fackler addresses this very problem:

Violation of simple, fundamental scientific method appears to be the common thread that runs through the misconceptions dealt with in this review. The author has found verifiable validity in only a small percentage of the material in print. The field of wound ballistics is part physics and part biological science. Considering the large proportion of "exact" science in wound ballistics, we should expect to produce a literature with more validity and reproducibility than other medical or "inexact" fields. Quite the opposite appears to have taken place. Failure to consider all the variables in the missile-tissue interaction, failure to use a control animal, failure to calibrate tissue simulants, failure to require data to support assumptions, etc.--these were the basic errors responsible for the misconceptions listed in the foregoing pages. The reader will probably agree that none of them involve a high degree of complexity.

In other words, ballisticians (and physicists) get it wrong, and doctors (and pathologists) get it wrong because they look at it from only a narrow viewpoint.

That was the crowning achievement of the Letterman Army Institute of Research. They brought the different fields together to study the problem. In doing so, Fackler became probably the world's foremost expert on terminal ballistics.

It's hard to argue with x-ray pictures of projectiles passing through living flesh, and the results of the subsequent necropsy (or treatment regimen).
 
I can't argue with either one of you on this topic, but I do have a supposition. If the pressure wave killed the animal then (I know this isn't referring to a bullet, but it's the closest real world example that I can come up with) if you shot a deer with a broadhead tipped 500 grain arrow, moving at 275 fps right behind the shoulder it would die, very quickly. If you shot that same deer in the same spot with the same bow and arrow and the arrow was tipped with a blunt tip, the arrow would bounce off the deer, or hit the deer and fall to the ground. When the arrow compeletely stopped it would transer all it's energy to the deer, where the broadhead tipped arrow would have passed through the animal thereby not delivering all it's energy to the deer. The deer shot with a blunt might have a heck of a bruise, but it won't be dead if the arrow doesn't penetrate. Clear as mud? Wouldn't the same be true for someone shot in the chest while wearing a Kevlar vest? Still gonna get the pressure wave, but not dead.
 
Lets put this in practical terms:

I have cleanly killed coyotes with
a 17 Ackley Hornet using Hornady 25 gr v-max,
17 Fireball using 25 gr and 30 gr bullets.
Tactical 20 using 30 gr and 32 gr bullets.
 
I can't believe you guys put that much work into an internet pissing contest, but whatever.
I have heard of 400 ft.lbs is what to shoot for, but don't know if it is true.
 
My isn't interesting how this whole conversation goes from- I want to cut them in half when I shoot them to as soon as fur season starts but i don't want hurt the fur. Let's face it a coyote is one tough customer, Blew a 2 IN hole on the back side of the lung area on the last coyote( lungs hanging out ) and it still managed to run about 40 YRD's. Now that tough!!
 
Originally Posted By: stevelynEnergy doesn't kill. Holes in vital organs do. If you put the holes in the right place it will die.

Steve, what you say, by and large, is true but you don't offer enough detail. The OP probably knows already that holes in the vital organs kill coyotes. Energy plays a role in this. And mere killing is not nearly enough. We want to quickly and humanely kill the animal. A 40 gr. .22 LR in the lungs will kill a coyote. A 40 grain V-Max or Ballistic Tip from a .223 or .22-250 into those same lungs will drop the animal like a ton of bricks. What's the main difference between those cartridges if it's NOT energy??? --- Mike
 
Originally Posted By: P SideOriginally Posted By: nmleonQuote:A bullet kills by hydrostatic shock, a pressure wave caused by the transfer of energy.

Negative sir. I know that's been a popular theory seemingly forever (or at least since I was a a boy which is close to forever), but it's an absolutely incorrect theory.

There has been way too much research done on terminal ballistics for "hydrostatic shock" to even be considered. Popular {mis}conception just hasn't caught up with reality yet.

Think of it this way, if hydrostatic shock was the killing force, Ir wouldn't matter where your bullet hit the target. A hit anywhere would kill because of that "pressure wave". That {obviously} is not the case.

You were compairing apples and oranges.
Than you and I will disagree. You don't need to go through both lungs to colapse both. You need both shot placement and energy to kill. Most of the research that has been done, has been with military non expanding rounds. Those rounds don't expand and transfer energy the same way hunting rounds do. You site no research.
That is why most States do not allow non expanding military style rounds to hunt big game. This is from the Illinois hunting regs. for hunting with handguns.
Quote:  For handguns, a bottleneck centerfire cartridge
of .30 caliber or larger with a case length not exceeding
1.4 inches, or a straight-walled centerfire
cartridge of .30 caliber or larger, both of
which must be available as a factory load with
the published ballistic tables of the manufacturer
showing a capability of at least 500 foot pounds
of energy at the muzzle. Note:There is no case
length limit for straight-walled cartridges.
 Non-expanding, military-style full metal jacket
bullets cannot be used to harvest white-tailed
deer; only soft point or expanding bullets (including
copper/ copper-alloy rounds designed
for hunting) are legal ammunition

As you can see, they believe there is a difference. If you shoot a fox with too much gun, you have a small entry wound. And a fist sized exit wound. The bullet doesn't expand that much, usually doubles in size. Or just watch video of a bullet going through ballistic gel. You can see an expanded wound channel. If there is research on hunting rounds I would really like to read it. If it was all about shot placement than everyone could hunt with a .22LR.

P Side, I agree with you. Do stay away from the term "hydrostatic" shock though. That one is FILLED with controversy...means different things to different folks.
When it comes to killing/stopping power, there IS more to the equation besides energy, but energy (impact energy to be more precise) is a BIG PART of the equation no doubt. As far as the bow and arrow comparison is concerned, I think it's a dead herring. First of all, the arrow is a very poor stopper to put it mildly and no one but no one ever thinks of using a bow and arrow to STOP dangerous game. Now, I wonder why? Could it be the PH's know something about the difference of killing and stopping? Heck, a couple months back, I was watching a video about bowhunting coyotes. I think there were a good 20 or more coyotes taken, just about every single one was hit well. Only two coyotes went down where they stood. One was hit in the head and the other I believe got spined. The others made tracks like there was no tomorrow. And these were double-lung'ed hits too! I saw that over and over and over again. Yes, I KNOW that everything up and including elephant has been taken by the bow and arrow...BUT...that video (and my eyes) didn't lie! The performance I saw would have been deemed mighty POOR had it delivered by a rifle!--Mike
 
Last edited:
Energy=Mass does apply. But not all the time. Would you rather have a 22 caliber bullet in a coyotes Brain fired from a 22 Magnum at 100 yards or a 45 caliber bullet fired at 100 yards from a 458 Winchester Magnum in the leg of a coyote?? It is not about energy. It is about bullet placement when hunting.
 
oh great. not another one of these. bullet placement is great but if you shoot fmjs it does significantly less damage than an expanding bullet.
 
Originally Posted By: greydogEnergy=Mass does apply. But not all the time. Would you rather have a 22 caliber bullet in a coyotes Brain fired from a 22 Magnum at 100 yards or a 45 caliber bullet fired at 100 yards from a 458 Winchester Magnum in the leg of a coyote?? It is not about energy. It is about bullet placement when hunting.

Why does it have to be a .22 bullet from a .22 Magnum at 100 yards? I knew a guy who killed a deer instantly with a .20 air rifle at 20 yards. The deer had been hit by a car and my friend decided to end the deer's misery. All he had was the air rifle in his truck. He shot it between the eye and the ear. The doe dropped dead instantly. The pellet was found just under the skin on the opposite side. If that had been a .177 pellet, the deer would have been just as dead, just as quick. So what's my point? When you're discussing killing/stopping power OF A CARTRIDGE, bringing up brain shots is really a red herring! When you're discussing placement of the bullet, you are discussing the experience (or lack thereof) and discipline OF THE SHOOTER and NOT the performance of the cartridge. However, and conversely, when we are discussing the killing/stopping power of a cartridge, we are discussing IT'S performance relative to the clean, quick, humane taking of game, predators, etc.. Basically, we are talking of chest shots (heart/lung). Why? For several reasons, first being that the heart/lungs shot is a much larger target. That's a big reason right there. Hunting conditions being what they are, a cartridge that can make clean kills on the LARGEST of vital organs is definitely a plus in our favor. Second, shots to the head of an animal DO NOT always reach the brain. Sometimes an errant bullet can take out a jaw and sometimes, on a frontal shot, a bullet can skid and be deflected. I remember shooting a big raccoon in a trap with .22 shorts, two hollowpoints and one solid. Took me three shots to get the job done at point blank range. I was shooting it from the front into the head. The third shot was the charm. Later when I skinned the critter, I actually SAW the skid marks on the skull where the bullet deflected away from the brain. In a hunting situation, I want a cartridge that can get the job done cleanly, quickly and humanely on a VERY CONSISTENT BASIS using well placed chest shots. For a brain shot, ALL I NEED IS PENETRATION. My friend's .20 airgun doe was killed instantly. In other words, not even a .460 Weatherby could have killed that deer any quicker! A .20 dome pellet makes a mighty small hole...in the brain, mighty small is still big enough.
We don't HUNT deer with .20 air rifles, or .22 shorts and hopefully, not even with .22 Magnums. We hunt them (and for the vast majority of hunters on this forum I'll wager the same is true) with rifles, shotguns, handguns and bows that can CLEANLY take them with chest shots.
Anytime you take a chest shot, you're going to need enough killing/stopping power from the cartridge/bullet combination. Anytime you discuss killing/stopping power, you're really discussing (IF THE DISCUSSION IS TO BE MEANINGFUL THAT IS) chest shots.
Chest shots require more, MUCH MORE, than just penetration alone. They require a wound channel WIDE ENOUGH (as well as deep enough) in order for the kill to be quick, clean and humane. In other words, chest shots require SUFFICIENT PERFORMANCE from the cartridge/bullet combination....and energy on impact is a PART of that performance. Hope this was helpful. --- Mike
 
Last edited:
Originally Posted By: Recko555I can't believe you guys put that much work into an internet pissing contest, but whatever.
I have heard of 400 ft.lbs is what to shoot for, but don't know if it is true.

That 400 ft.lbs. figure was written by Rick Jaimison who used to write for Shooting Times. Rick was and is one EXTREMELY savvy writer and, for one season, actually made his entire living on nothing else but called-in coyote hides. It was just something he had to do to see if he could do it. He'd hunted coyotes since he was a kid and was mighty adept at it...but, still wanted that challenge. He wrote a book on the subject too (long out of print as far as I know). Rick wasn't saying that 400 was precisely the minimum. What I remember from his articles where he used that figure, he was delving from his (considerable) experience and came up with what he felt was a USEFUL number. Of course, different bullets at that same 400 fps can and will render different performance but he assumed that the reader would use a bullet that would perform properly at that impact energy. I have that book and read many articles by the man and I can tell you, he was a middle of the roader in his choice of cartridges and bullets. The rifle he used for that full time season was a Remington 788 in .22-.250 with a 3x-9x scope, Canjar trigger and 52 grain Match hollowpoint bullets. He took chest shots only and was adamant about that. The 400 figure was meant to be helpful and useful, not definitive. ---Mike
 
I seen my brother in law shoot a dog broadside at 40 yards and down he went, waiting for the other one to come clear, i shot the other one, down plop. As we quit calling to go get the dogs the first one jumps up and heads for the next county, it was shot with a 50gr vmax out of a Ruger compact 16 1/4in barrel, so not really high velocity, moral of story, I believe the [so called energy knocked this dog out but did not penetrate at all, I believe the bullet has to match the velocity or the so called energy is wasted. ed
 

Thanks Tunered! Great example! A bullet has to match the velocity or the energy gets wasted...great point. You got that coyote but I'm sure you wouldn't want to hang your hat on zero penetration, shot-in, shot-out! Same thing applies with using fmj bullets or solids on medium game. Heck, I remember shooting about a half a dozen fox squirrels with .22 LR (solids) in the chest before it finally dawned on me that I had ALL the energy I needed; I just needed a better TRANSFER of that energy. In my situation, I was given a brick of .22 LR solids for Christmas and figured to use them up hunting before I switched to hollowpoints. Good intentions...bad idea! Those squirrels (all 6) acted like they received no hit at all. All six times, I shot for behind the shoulder. All six remained totally motionless as though no hit had occurred. Through my scope, I could see no indication of impact. All six squirrels got a follow-up in the head and yes, all six squirrels had a neat little bullet hole in the lungs. Yes, fox squirrels ARE mighty tough little critters, about as tough ounce for ounce as it gets. A .22 LR high velocity gets somewhere around 140-150 ft.lbs. at the muzzle and these shots were taken at around 20-30 yards. Plenty of energy but not nearly enough energy TRANSFER to the vitals! Contrast that mediocre performance with that of any .22 LR hollowpoint load (high velocity or subsonic) and the difference is like night and day. For that matter, contrast it with my Beeman RX-1 using .20 Crow Magnum pellets at 20ft.l.bs. and my Beeman Kodiak using .25 Crow Magnum pellets (or any other pellet for that matter...25 is wicked in airguns) at 25+ ft.lbs. on fox squirrels at the same ranges using the same shot placement. The airguns with only a fraction of the LR's energy are truly WICKED killers on 2-3 pound fox squirrels taking them with authority. The Crow Magnum pellets expanded well in the squirrels out to well over 30 yards.
Energy charts are and can be useful/helpful but need to be taken with a HUGE grain of salt and a healthy dose of common sense! Thanks for posting! --- Mike
 
Shot a deer with a AIR GUN?????????????? Is that even legal in any state in the Union??? If bullet placement is not important then just use a 155MM Howitzer. You only need to be close then.
 
Back
Top