Author Topic: Energy and what it does to game  (Read 10061 times)

deerman

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Energy and what it does to game
« on: March 15, 2013, 12:05:35 PM »

Some time back on "that other board" there was quite a discussion about "what energy of a bullet has to do with killing game."

A certain knowledgable hunter had some pretty strong opinions on the subject.  Now I see an article in "The Outdoor Edge" about the sunject.

"WHAT'S ENERGY GOT TO DO WITH IT"

I think he makes some valid points but at the same time over looks some things.  Perhaps he has talked to some folks who were convinced that energy was the only thing that mattered and it is what killed game.  Which I think is wrong.  However to over simplify things and suggest that "killing is still done by nothing but mechanical means" is also wrong.


Just thought I'd start a thread to talk about what we think or understand about what a bullet does inside game and how that results in killing and recovering game.

If you disagree with any views expressed on here there is no need to go beyond the difference of opinion to personal comments.  And if you know the article and author there is no need to make personal comments about them.

Weste

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Re: Energy and what it does to game
« Reply #1 on: March 15, 2013, 01:22:31 PM »
Do you have a link to the article?  I wouldnt mind reading it before any comments.  Thanks

walleyes

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Re: Energy and what it does to game
« Reply #2 on: March 15, 2013, 02:27:43 PM »
Its pretty cut and dry as far as I am concerned.. The wound channel kills. Yes energy sends the projectile that causes the wound channel but in the end its the wound channel that kills. Energy can possibly knock an animal down or slow it down but it will not die from energy. Now it also takes more energy to send a larger projectile farther distances, i.e a .30 cal bullet out to 300 yrds vs a .22 cal bullet 50 yards so to that effect energy is needed. But again, put a .22 cal bullet to the head of most any animal and it will die unless the wound channel is not sufficient to cause enough damage. It could be argued that with more energy we get more drastic wound channels,, well yes, but regardless,, its still the wound channel that does the killing.

I do find this topic very interesting and peoples inabillity to grasp its concept.

Paul

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Re: Energy and what it does to game
« Reply #3 on: March 15, 2013, 02:59:00 PM »
I agree with walleyes, it's the bleeding that kills  ;D

BruceW

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Re: Energy and what it does to game
« Reply #4 on: March 15, 2013, 03:02:20 PM »
I don't care much about muzzle energy, it's the downrange remaining energy at the distance I expect to be shooting my quarry that I consider.  For elk, I like a 300wm with a 180gr Partition for that very reason.  I think it's a very good compromise of trajectory/remaining energy.

For moose, I prefer my 450 marlin pushing a 400gr Hawk with all the 3031 I can stuff into the case(a little tongue in cheek). 

If you look at ballistic charts and compare both energy and trajectory of different calibres, a 30-06 pushing a 220gr lead at just under 2600fps muzzle vel. is a heck of a fine "brush gun", in fact, on paper one of the best, IMO.  That being said, When you compare it at 60yds to my 450/400gr lead, well, it's an obvious choice to me for my intended purpose.

Far as energy/wound channel, on the one hand you really only need enough energy at impact for the bullet to act properly and create the desired wound channel;  you could say the minimum goal is to find the bullet on the opposing side, just under the hide.  On the other hand, there's a lot to be said for the pure, "shock" energy as well.  My example would be, would you rather be hit with a pebble going a hundred miles/hr, or a 5lb rock dropped 10'?  It's an interesting topic.

I always just try to use what I feel would be the best tool for the job;  work on my loads to find the best results ballistically, then check the bullet performance at that load using milkjugs filled with water and a tightly newspaper filled catch box at the end.  I've learned a lot doing that. 

As to the original question, my take would be:  assuming good bullet performance and shot placement being equal, more than minimum energy is not necessarily required, but does give a big advantage in taking game.  In other words, with energy is bigger better?  Yes, as long as that increased energy doesn't mean impact at a speed that doesn't allow the bullet to perform as it's intended.

So I guess I didn't say anything we all didn't already know, eh?  :)

AxeMan

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Re: Energy and what it does to game
« Reply #5 on: March 15, 2013, 03:55:50 PM »
I debated this topic with the writer that you mentioned and was very frustrated with some of the dialog that was being thrown around.  I worked in a physics department for many years in a post secondary institute and the grasp this man had on physics concepts was questionable.  I got sick of arguing about some simple facts of physics.

Basically, what Walleyes just stated is all we really need to know in practical terms.

Just remember that E=(1/2)mv2.  That is mass times velocity squared divided by 2.
And energy is always conserved.  If a bullet is totally stopped by the animal, all of its kinetic energy is transfered in creating a wound channel, deforming the bullet, and imparting some motion into the flesh.  If the bullet passes through, then only part of the total kinetic energy is transfered to the animal and part remains with the still travelling bullet.

It always ends up being a discussion on how the transfered energy from the bullet to the animal does the killing.  The energy transfer is a very dynamic process with a ton of variables and results in a permanent wound channel, a temporary displacement of tissue (shock waves), bullet deformation, some noise and heat (small amount). 

The mechanical damage that the bullet does to flesh is a combination of physical contact (tearing) and also the rapid violent displacement of the flesh in the vicinity of the bullet path.  The permanent damage is a combination of these two factors mostly. The rapid displacement of the flesh in the wound area is often referred to as "shock".

Factors such as bullet construction and density, velocity, flesh and bone density all are major factors in creating permanent wound channels and shock waves in the flesh.  Some people claim that the shock waves that are created in the flesh and anatomy of the animal that don't directly result in the permanent wound channel, do not contribute to killing.  I believe it is a factor to a smaller extent in some cases where the nervous system may be affected. 
« Last Edit: March 15, 2013, 04:27:29 PM by AxeMan »
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deerman

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Re: Energy and what it does to game
« Reply #6 on: March 15, 2013, 05:20:19 PM »
Do you have a link to the article?  I wouldnt mind reading it before any comments.  Thanks

Could not find a link to the article.  afga.org will show you the recent issue of Outdoor Edge and the content of it but not the whole article.



As stated above what a bullet does in flesh is a complicated thing and we can only look at the results in ballistic jell and somewhat in the animal and its reactions, then make assumptions.

You can see by my original question I am not just interested in a very simple partial answer like "the bullet makes a wound channel and the game bleeds to death".

I believe the energy transfer from the bullet to the animals body, while it may not be the ultimate cause of death, is a factor in over all circumstances of the death process.

For example I have seen animals shot with a .243 that did not provide an exit hole to cause a blood trail.  They died but were hard to locate.  So I feel the bullet construction and perhaps lack of energy did not allow for a pass through and hindered recovery of the animal.

JIMMY 808

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Re: Energy and what it does to game
« Reply #7 on: March 15, 2013, 05:55:29 PM »
The answer lies in humans as the test medium.  There is hundreds of thousands of case studies difficult to access but itís there.  Lots of hand gun cartridges have been made with certain velocity criteria for the bang flop factor.  Start reading up on the 357 sig 357 magnum US border patrol Mexico.   

walleyes

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Re: Energy and what it does to game
« Reply #8 on: March 15, 2013, 06:15:05 PM »
Could not find a link to the article.  afga.org will show you the recent issue of Outdoor Edge and the content of it but not the whole article.



As stated above what a bullet does in flesh is a complicated thing and we can only look at the results in ballistic jell and somewhat in the animal and its reactions, then make assumptions.

You can see by my original question I am not just interested in a very simple partial answer like "the bullet makes a wound channel and the game bleeds to death".

I believe the energy transfer from the bullet to the animals body, while it may not be the ultimate cause of death, is a factor in over all circumstances of the death process.

For example I have seen animals shot with a .243 that did not provide an exit hole to cause a blood trail.  They died but were hard to locate.  So I feel the bullet construction and perhaps lack of energy did not allow for a pass through and hindered recovery of the animal.

In the end it's no more complicated than the fact that the bullet made a hole and the animal bled to death. We can put all the big words into we want but that is what happened no more technical than that. The fact a bullet didn't go through an animal has no end result in that animal dying. I packed a .270 win around for years and shot well over a dozen moose with that rifle,, rarely did I get a pass threw. Most animals died with in a few yards, the odd one may have required a bit of a stock none could of been that bad because I don't recall any. If an animal has a hole in the lungs,, it can't live,, that simple. Now if you have poor bullet design and the bullet doesn't expand properly and make a sufficient wound then we blame the bullet not the energy.

Yes we strive to own rifles that pack a lot of energy,, for me personally I look for a rifle or cartridge that carries enough energy down range to inflict a wound channel to cause death, the flatter the gun shoots the better it is so more energy required to do so but still in the end I am looking for one thing,, a hole in its lungs so it bleeds to death and that's all.

Deputy sheriff

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Re: Energy and what it does to game
« Reply #9 on: March 15, 2013, 07:50:51 PM »
I am by no means an expert,but I believe what a bullet does inside an animal is best described as hydrostatic shock.This is caused by a bullet retaining most of its energy, before it exits the animal,inside the animal.Blood cannot be compressed and therefor hydraulically  forces blood to the nearest organs or tissue and they rupture.If the bullet makes contact with bone and has enough power it will cause the bone fragments to become projectiles.Many of us have seen the heart of a animal that looks like a chainsaw tore through it, this is what hydrostatic shock does.
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BruceW

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Re: Energy and what it does to game
« Reply #10 on: March 15, 2013, 08:10:13 PM »
Now if you have poor bullet design and the bullet doesn't expand properly and make a sufficient wound then we blame the bullet not the energy.

That's where it gets complicated.  Testing different bullets/calibres/loads into waterjugs/newspaper has taught me that a bullet that performs properly at one impact speed may fail miserably at another.  Some require a lot of impact speed to function, others fail at greater impact speeds. Also keep in mind a light bullet weight, even going warp 9 loses energy unbelievably fast, the old mass times acceleration thing.  Testing actually changed the bullets I use for hunting.

Sort of off Deermans original topic maybe but pertinent nonetheless, for a bullet that does an excellent job of transferring energy into damage at 60yds may fail completely at 250yds and less impact velocity, or vice versa.

walleyes

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Re: Energy and what it does to game
« Reply #11 on: March 15, 2013, 08:33:10 PM »
Yes that's understandable Bruce but again the energy is used for the bullet to do its job,, the result from that energy being placed in the bullet causes it to expand causing adequate damage (wound channel) to cause enough damage  to cause death.

Sonny

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Re: Energy and what it does to game
« Reply #12 on: March 15, 2013, 09:38:21 PM »
I agree with walleyes, it's the bleeding that kills  ;D

Yup,interupt the blood flow to the brain and it's game over.

honkerhitter

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Re: Energy and what it does to game
« Reply #13 on: March 15, 2013, 10:17:52 PM »
Yes that's understandable Bruce but again the energy is used for the bullet to do its job,, the result from that energy being placed in the bullet causes it to expand causing adequate damage (wound channel) to cause enough damage  to cause death.

Walleye Ill give you that one holes kill ,  where does tracking from thru and thrus compared to bang flops come into the fold.  Personally I think Axeman explained it well, and in an understandable context .
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deerman

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Re: Energy and what it does to game
« Reply #14 on: March 15, 2013, 10:53:05 PM »

Not nearly enough events to be of scientific value but I have shot a number of deer and a few pronghorn with muzzleloaders.

Those shot with the more primitive types had a hole put through them and ran off some distance to die from blood loss.  Those shot with an inline with a saboted "modern bullet" propelled by 150 grains of pyrodex were "bang flop" type kills.  They may have ultimately died from blood loss but they did so right there in my sight without moving off.


I have shot a number of white-tails with a .35 whelen and 250 grain factory ammo.  They all eventually died from the holes in them and bleeding but all required additional shots and ran off to die.  No "bang flops".  I believe the bullets were going through them without expanding and imparting energy to their tissue.

walleyes

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Re: Energy and what it does to game
« Reply #15 on: March 16, 2013, 09:24:16 AM »
Personally at times I believe we put to much stock in the bullet and cartridge and not enough attention or regard if you will is given to the animal itself and I believe we all to often will blame bullet design rather than say we made a bad shot. There are so many variables than can come into play and most of them can be afforded to the shooter or the game.

I have never been a guy to experiment a lot,, I find what I like and what works and I stick with it. Growing up in a small town in the late 70ís and 80ís we never had a lot of options when it came to purchasing shells, we bought what there was at the best of times we may of had 2 or 3 choices in any given caliber. Funny thing is I donít recall losing anymore game back then than I do now with all these fan dangled bullet designs we have. Like I stated I packed one rifle for many years 16 years to be exact. Probably only shot about 3 or 4 different bullet designs regularly through that gun and as such one has the ability to study results based not on different bullets but on the game itself. I shot Federal 150g round nose soft points for years, then switched to the Winchester Ballistic silver tips. Shot those out of that gun for years. Over the years using these shells I shot numerous game animals ranging from many whitetail, probably 20 or so, some where around a dozen moose and quite a few bear. In those kills there were many different kill results with the same bullet, some bang flops, some short stocks some 100 - 200yrd stocks and one lost animal, a moose. Some pass throughs most not on moose lots on deer. My point is, is there are no 2 kills exactly the same and this using the same bullets and rifle. I think all to often we may get a poor kill and blame the bullet or cartridge and switch to something else never getting the proper info. Far be it from us to blame the obvious,, us, or to think that one animal can be stronger than the last. To think that all animals in a species have the same tolerance is absurd thatís like saying all humans are equally as strong.

After the .270 I switched to my .300 RUM now when it comes to standard rifles its hard to pack one that delivers more energy than a .300 RUM. Funny thing is we end up with the same results,, some bang flops, some short stocks, definitely more pass throughs but regardless same results. I can not say that do to the severe increase in energy the kills went up nor did the bang flops the only thing that went up was damaged meat from poorly placed shots, ie shoulder shots,, but thatís another topic. The first year I had all that energy I was out with my boys, they were young at the time. We were at a neighbors looking for a meat buck. I shot a young buck at about 150 yrds, ripped the brisket basically off that little buck. That buck ran a good 400yrds across the field until it expired,, not enough energy ? or an excited animal and a a less than perfect shot ?

Sorry for the long winded post but I think you get the point. Just because an animal does not expire on the spot or bang flop dead we can not just look at the bullet or the energy, all factors must be taken in to consideration.

Lurch

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Re: Energy and what it does to game
« Reply #16 on: March 18, 2013, 06:29:23 AM »
I debated this topic with the writer that you mentioned and was very frustrated with some of the dialog that was being thrown around.  I worked in a physics department for many years in a post secondary institute and the grasp this man had on physics concepts was questionable.  I got sick of arguing about some simple facts of physics.

Basically, what Walleyes just stated is all we really need to know in practical terms.

Just remember that E=(1/2)mv2.  That is mass times velocity squared divided by 2.
And energy is always conserved.  If a bullet is totally stopped by the animal, all of its kinetic energy is transfered in creating a wound channel, deforming the bullet, and imparting some motion into the flesh.  If the bullet passes through, then only part of the total kinetic energy is transfered to the animal and part remains with the still travelling bullet.

It always ends up being a discussion on how the transfered energy from the bullet to the animal does the killing.  The energy transfer is a very dynamic process with a ton of variables and results in a permanent wound channel, a temporary displacement of tissue (shock waves), bullet deformation, some noise and heat (small amount). 

The mechanical damage that the bullet does to flesh is a combination of physical contact (tearing) and also the rapid violent displacement of the flesh in the vicinity of the bullet path.  The permanent damage is a combination of these two factors mostly. The rapid displacement of the flesh in the wound area is often referred to as "shock".

Factors such as bullet construction and density, velocity, flesh and bone density all are major factors in creating permanent wound channels and shock waves in the flesh.  Some people claim that the shock waves that are created in the flesh and anatomy of the animal that don't directly result in the permanent wound channel, do not contribute to killing.  I believe it is a factor to a smaller extent in some cases where the nervous system may be affected.

That's actually a very good answer.

And before anyone trumpets the article from the self professed expert, bear in mind he has only hand loaded a couple of years and basically has argued with every one of us with ballistic/bullet performance - largely with published data (as he shot factory ammo).

I think he has dabbled lightly in hand loading now - and perhaps does some ballistic testing with his other equally annoying buddy. I by no means consider this to make him overly qualified.

I would be far more inclined (and likely better suited) to believe the experiences of many here.

JIMMY 808

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Re: Energy and what it does to game
« Reply #17 on: March 18, 2013, 09:07:44 AM »
As writers in general are sponsored in some form or another I take anything written with a grain of salt.
 
I have stated in this thread before were to look for scientific analyses of what happens when bullets impact.     
« Last Edit: March 18, 2013, 09:31:49 AM by JIMMY 808 »

walleyes

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Re: Energy and what it does to game
« Reply #18 on: March 18, 2013, 01:35:30 PM »
I have always had a problem with sponsored writers and their product reviews or opinions on said products. It is imposible for them to be unbiased, they would be broke.

alkali

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Re: Energy and what it does to game
« Reply #19 on: March 18, 2013, 08:24:07 PM »
This is one that always confuses the hell out of me. A full metal jacket bullet and and expanding one, same size and speed have the same energy if I understand it correctly. Why then does the expanding one kill beter if energy is doing any of the killen?