Does Energy have the potential to affect terminal performance?

[10E]

I would argue even energy and velocity might not be enough to answer the question. You really need to know what bullet and what are its optimal conditions. I used a load this year that was 1000fps and 1000ftlbs and I would use it on elk any day. I am sure that a 2000 fps load might not work well depending on the bullet, say a TSX.

I agree 100%. I guess that is another question I have. If we can accurately predict terminal performance with bullet construction, velocity, and target medium. What is the formula to achieve the optimal results on a larger scale? Say I didn’t have a 223 but I have a 6 creedmoor. What would be optimal bullet choice and velocity window for this cartridge?

 

[10E]

You've been an easy read from the start. Sort of like a dumb AI troll. Easy to predict you would conclude that.

I apologize that I have hurt your feeling so bad that you felt the need to say that. That was not my intentions.

 

[chamois]

Talking about energy and its transfer, or where does it go, or how much is lost in the air when you get a pass through, and cliches like that, I would like to ask what % of the kinetic energy is actually absorbed by the bullet itself in its deformation/fragmentation process.
It is not a recurring question as I really don't know, but my guess would be a high percentage.
And another non recurring question would be how much energy will be dissipated as heat.
I think energy has several funny faces, some quite difficult to translate into physical effects.

 

[Chris_in_Idaho]

I think what the 223 thread has taught us is the actual "work" of disrupting tissue to create a very effective wound channel doesn't take much kinetic energy at all. The 77tmk impacting at 1800fps which has shown to be so extremely effective in the 223 thread carries a miniscule 554 ftlb. Form has shown good results from even slower impacts carrying energy in the 300s of ftlbs, and these lower impact velocities aren't recommended against because of a lack of energy, but because the TMK bullet might not upset as reliably.

What I'm gathering from that is any cartridge combination that we would remotely consider for hunting has more than enough energy to make a very effective wound. The issue is that many bullet designs don't do a good job of using that energy to make a wound.

*If a bullet passes through, it took energy with it that did not get applied to the animal, and did not contribute to a wound.

*If the animal gets physically moved, pushed sideways, has to move its feet to keep balance, etc, then bullet KE transferred into animal KE and didn't contribute to a wound.

*If a bullet does transfer energy in the form of a big temporary cavity, but that temp cavity snaps right back and doesn't become a permanent cavity, that energy didn't contribute to a wound.

*If a bullet explodes Varmint style and does not reach the vitals, then it did use most of its energy to create a wound, but failed to put the wound in the right place to be effective.

So, energy isn't a useful number because we simply already have enough of it. What we DO need to know is whether or not our bullet is going to do an effective job of using some of that energy to make a good wound.

This question comes down to bullet construction, mass, and IMPACT VELOCITY. Everything about the bullet hinges on how fast it impacts. Not because of KE, but for how the bullet itself will be react to the collision with the animal. Think of it as: "is the elk going to smack the front of the bullet hard enough to change the bullet's shape into an effective wounding device?"

 

[Formidilosus]

It’s very easy-

I agree 100%. I guess that is another question I have. If we can accurately predict terminal performance with bullet construction, velocity, and target medium.

Without shooting the bullet into a correct target medium and measuring the wound created, you have little idea of what will happen.

Shoot bullets into properly calibrated 10% organic gelatin at max muzzle velocities, mid range impact velocities, and low impact velocities. Do it in bare gel or gel with heavy clothing (normal impact in animal), and with plywood or glass in front of gel (the worst possible condition).

Measure the wound like this-

(Courtesy DR. Gary K. Robert’s)



For big game animals in NA including elk and moose-

1). A minimum of 12-14” of penetration. If a bullet makes it to 12” after going through plywood or especially auto glass, it will make it through any bone in the front half of an elk, moose, bear, or any other game animal. “Shoulders” are a joke.

2). The widest wound possible for that depth. That will create the most tissue damage and the quickest incapacitation times on average. Go bigger in caliber/cartridge/grain but maintain the same depth of penetration and increase the width- more meat damage is created. That increase generally doesn’t result in faster incapacitation times once a certain point is reached, until extreme damage occurs.


Properly calibrated gel shots overlayed in a mule deer. Same caliber, cartridge, impact velocity, and “energy”.

These are at very high impact velocity. Which one kills faster?

 

[Chris_in_Idaho]

It’s very easy-


Without shooting the bullet into a correct target medium and measuring the wound created, you have little idea of what will happen.

Shoot bullets into properly calibrated 10% organic gelatin at max muzzle velocities, mid range impact velocities, and low impact velocities. Do it in bare gel or gel with heavy clothing (normal impact in animal), and with plywood or glass in front of gel (the worst possible condition).

Measure the wound like this-

(Courtesy DR. Gary K. Robert’s)
View attachment 649830


For big game animals in NA including elk and moose-

1). A minimum of 12-14” of penetration. If a bullet makes it to 12” after going through plywood or especially auto glass, it will make it through any bone in the front half of an elk, moose, bear, or any other game animal. “Shoulders” are a joke.

2). The widest wound possible for that depth. That will create the most tissue damage and the quickest incapacitation times on average. Go bigger in caliber/cartridge/grain but maintain the same depth of penetration and increase the width- more meat damage is created. That increase generally doesn’t result in faster incapacitation times once a certain point is reached, until extreme damage occurs.


Properly calibrated gel shots overlayed in a mule deer. Same caliber, cartridge, impact velocity, and “energy”.

These are at very high impact velocity. Which one kills faster?

View attachment 649831

View attachment 649832

But what about all that rib meat I was going to wafer out with my exacto knife?

Just kidding, very persuasive pictures.

 

[Mike Islander]

I apologize that I have hurt your feeling so bad that you felt the need to say that. That was not my intentions.

Totally predictable. Apology accepted.

 

[10E]

It’s very easy-


Without shooting the bullet into a correct target medium and measuring the wound created, you have little idea of what will happen.

Shoot bullets into properly calibrated 10% organic gelatin at max muzzle velocities, mid range impact velocities, and low impact velocities. Do it in bare gel or gel with heavy clothing (normal impact in animal), and with plywood or glass in front of gel (the worst possible condition).

Measure the wound like this-

(Courtesy DR. Gary K. Robert’s)
View attachment 649830


For big game animals in NA including elk and moose-

1). A minimum of 12-14” of penetration. If a bullet makes it to 12” after going through plywood or especially auto glass, it will make it through any bone in the front half of an elk, moose, bear, or any other game animal. “Shoulders” are a joke.

2). The widest wound possible for that depth. That will create the most tissue damage and the quickest incapacitation times on average. Go bigger in caliber/cartridge/grain but maintain the same depth of penetration and increase the width- more meat damage is created. That increase generally doesn’t result in faster incapacitation times once a certain point is reached, until extreme damage occurs.


Properly calibrated gel shots overlayed in a mule deer. Same caliber, cartridge, impact velocity, and “energy”.

These are at very high impact velocity. Which one kills faster?

View attachment 649831

View attachment 649832

This is awesome information thank you for sharing this and answering my question. A simple answer is we do not know with certainty which one will kill faster. The only way to prove one way or another would be to fix/control certain variables. Which honestly goes too far off track of what would be practical or possible in a hunting situation.

Honestly this is one of the most profound things I have gathered from this discussion. In a way I can prove or disprove most theories by fixing or unfixing certain variables. Fact as we know it is largely dependent on the fixing of certain variables to achieve a replicable/reliable/proven outcome. This applies to more than just firearms and bullets.

This ties in with the no perfect bullet idea. I can find situations/variables where it would “fail” in a “hunting situation”. These terms are very general.

This was the first mistake I made when commenting on the forum. In a way I was trying to force my own personal balance of all of my own “fixed variables” onto someone else. I hope that makes sense. I apologize to everyone. That attempt was wrong and somewhat useless discussion.

223 77 gr TMK is an excellent example of something working quite well when certain variables are fixed. It holds up to much larger cartridges/bullets in terms of the results. The variables that were fixed were very clearly laid out at the beginning of the experiment as well as the advantages of using that combination. In that way the experiment could be proven factual/ reliable/ replicable. Which it is/was.

As a side note I would like to think (not always the case though) that some of the gun writers tend to speak from not only personal experience but the observations of fellow hunters etc. In very general terms leaving the variables somewhat unfixed for the term “rifle (insert species) hunting”. In that case the most balanced or middle ground is probably the safest information for the very wide margin of unfixed variables. Not all hunting strategies/types/situations/ scenarios are the same so they have to speak in very general terms to cover their bases.

 

[Drenalin]

This is awesome information thank you for sharing this and answering my question. A simple answer is we do not know with certainty which one will kill faster. The only way to prove one way or another would be to fix/control certain variables. Which honestly goes too far off track of what would be practical or possible in a hunting situation.

Honestly this is one of the most profound things I have gathered from this discussion. In a way I can prove or disprove most theories by fixing or unfixing certain variables. Fact as we know it is largely dependent on the fixing of certain variables to achieve a replicable/reliable/proven outcome. This applies to more than just firearms and bullets.

This ties in with the no perfect bullet idea. I can find situations/variables where it would “fail” in a “hunting situation”. These terms are very general.

This was the first mistake I made when commenting on the forum. In a way I was trying to force my own personal balance of all of my own “fixed variables” onto someone else. I hope that makes sense. I apologize to everyone. That attempt was wrong and somewhat useless discussion.

223 77 gr TMK is an excellent example of something working quite well when certain variables are fixed. It holds up to much larger cartridges/bullets in terms of the results. The variables that were fixed were very clearly laid out at the beginning of the experiment as well as the advantages of using that combination. In that way the experiment could be proven factual/ reliable/ replicable. Which it is/was.

As a side note I would like to think (not always the case though) that some of the gun writers tend to speak from not only personal experience but the observations of fellow hunters etc. In very general terms leaving the variables somewhat unfixed for the term “rifle (insert species) hunting”. In that case the most balanced or middle ground is probably the safest information for the very wide margin of unfixed variables. Not all hunting strategies/types/situations/ scenarios are the same so they have to speak in very general terms to cover their bases.

Gunwriters sell bullshit. Their job is to hit a word count, create a clickbait title, or present something insignificant as being significant so people buy, click, etc.

 

[10E]

Gunwriters sell bullshit. Their job is to hit a word count, create a clickbait title, or present something insignificant as being significant so people buy, click,

I think your statement reinforces my main point from a different perspective. Most of us have seen that when it comes to selling someone on a product or persuading someone. A fact can be very persuasive for some people. Generally (by no means all) they list true facts learned/observed/ tested from a fixed set of variables that usually make the product or idea look better/more appealing. Or that give it an apparent advantage over another product. What I’m trying to say is I can basically get the answer I want to relay by carefully selecting and fixing the variables or criteria. We can call that bs or whatever you like I honestly don’t care.

Think of new cartridge comparisons with existing cartridge comparisons over the years. They relay tested/proven/provable facts but the variables are fixed in such a way to make that product or idea appear better. (Heavier or lighter bullet, higher bc, tighter twist, more or less velocity, factory available, less recoil, more penetration or less penetration, on and on)

Please do not take this the wrong way I’m not saying anyone that started or contributed to the 223 thread is making money off of it. Or that their intention was to sell anyone on anything. I will add that within the clearly defined fixed variables/criteria listed in that thread that cartridge/bullet works wonderfully. It is proven/verifiable.

Many people were willing to try it because of the known/ verifiable/ proven merits shown in that thread and a lot found that it fit their criteria better than what they were using. Which I think is great!

This is where I was wrong. My criteria may differ enough from that listed that it is not the optimal choice for me or what I may expect to encounter, but I can only say that for myself.

That brings me to the last point. We all have our own set of variables and criteria. What is optimal or balanced for me may not be optimal or balanced for you. We may have different hunting techniques or strategies that could greatly affect the “right” answer (if one exists) for us.

hopefully that makes sense.

 

[wind gypsy]

A 77 TMK and a 175 TMK at the same impact velocity have energy difference that is at the same ratio to the bullet weight difference. Based on that I have a hard time understanding what energy would tell a person that bullet weight doesn't already tell them?

I'm generally curious though, given the above mentioned bullets at say 2500 FPS impact velocity - does the volume or amount of tissue damage scale relatively accurately with bullet weight?

 

[General RE LEE]

That’s correct and that is the problem. Correct upset velocity is the determiner, not Ft-lbs energy. Hornady ELD-M’s and ELD-X as well samples all need 1,800fps to reliably upset- that is regardless of of caliber or weight. From .224 to .338 that all need the same impact velocity. Yet the ft-lbs of energy for each bullet at 1,800fps impact is all over the map. From 550 ft-lbs for a .224 75gr ELD-M, to 2,054 Ft-lbs for the .338 cal 285gr. Yet, the both those bullets upset properly at 1,800fps.


Ft-lbs of energy is a “useless” metric because it doesn’t tell anyone anything about what a bullet will do in tissue. To know know what a bullet does in tissue it must be shot into tissue or properly calibrated tissue simulate at varying impact velocities and have the wounds that are created measured.
Once you do that, it does not matter how much “energy” it had or didn’t have. The wound is what matters.

I was going to start a new thread but this answered a question I had perfectly. Hornady markets the ELD-X as reliably expanding down to 1600 FPS. In my 30-06 with the 178 grain ELD-X, my KE at 1600 FPS is over 1K foot lbs. I guess the 1K lbs of energy doesnt equate to helping a bullet expand. It's the velocity.

I'm going to stick with 1800 FPS as Form suggests. I just got a 6mm ARC and thankfully does well with the 108 ELDMs. It hits 1800 FPS at 500 yards which is a good threshold for my hunting needs.

 

[eric1115]

I guess the 1K lbs of energy doesnt equate to helping a bullet expand. It's the velocity.

This is exactly right. A 103 grain ELDX has approx half the energy of a 212 ELDX at the same 1600 fps, but they both upset at that velocity.

A 212 ELDX will upset very poorly at 1100 FPS, despite having the same 575 ft lb of energy as a 103 ELDX at 1600 FPS.

 

[Lou270]

I was going to start a new thread but this answered a question I had perfectly. Hornady markets the ELD-X as reliably expanding down to 1600 FPS. In my 30-06 with the 178 grain ELD-X, my KE at 1600 FPS is over 1K foot lbs. I guess the 1K lbs of energy doesnt equate to helping a bullet expand. It's the velocity.

I'm going to stick with 1800 FPS as Form suggests. I just got a 6mm ARC and thankfully does well with the 108 ELDMs. It hits 1800 FPS at 500 yards which is a good threshold for my hunting needs.

This is exactly right. A 103 grain ELDX has approx half the energy of a 212 ELDX at the same 1600 fps, but they both upset at that velocity.

A 212 ELDX will upset very poorly at 1100 FPS, despite having the same 575 ft lb of energy as a 103 ELDX at 1600 FPS.

This is not true exactly. Velocity does not really expand anything. The reason velocty is important is dynamic pressure. Basically in a fluid or semi fluid, the faster something impacts the “harder” it is because the material can’t get out of way fast enough. Dynamic pressure increases with v^2. If the dynamic pressure at impact is higher than the pressure required to deform the bullet - then you get expansion (i.e. energy transfer/work). As a bullet penetrates and slows down the dynamic pressure decreases. The softer the bullet the more it needs to slow down before stops deforming. Think about it -> you can hit a steel plate with much lower than 1500 fps and a bullet will come apart because there is plenty of energy to do so and the plate is harder than the bullet despite the bullet may not deform in flesh. Otherwise, the dynamic pressure required to make a fluid harder at impact than a bullet designed to expand is at a velocity where the energy is high enough to expand the bullet easily. This is also why bullets can come apart prematurely at high impact velocities and light construction. Copper is much harder than lead and the reason used in varying degrees of thickness to control how much a bullet deforms. This is also why mono bullets do not deform as much as lead/copper jacket bullets - they expand quickly due to high dynamic pressure at impact but due to being harder stop expanding at a higher velocity during penetration while a lead/copper bullet may keep expanding down the shank or come apart totally. In either case the full deformation happens very quickly once it starts and done in first several inches after which the bullet / pieces go on in whatever their terminal shape is.

Lou

 

[Chris_in_Idaho]

This is not true exactly. Velocity does not really expand anything. The reason velocty is important is dynamic pressure. Basically in a fluid or semi fluid, the faster something impacts the “harder” it is because the material can’t get out of way fast enough. Dynamic pressure increases with v^2. If the dynamic pressure at impact is higher than the pressure required to deform the bullet - then you get expansion (i.e. energy transfer/work). As a bullet penetrates and slows down the dynamic pressure decreases. The softer the bullet the more it needs to slow down before stops deforming. Think about it -> you can hit a steel plate with much lower than 1500 fps and a bullet will come apart because there is plenty of energy to do so and the plate is harder than the bullet despite the bullet may not deform in flesh. Otherwise, the dynamic pressure required to make a fluid harder at impact than a bullet designed to expand is at a velocity where the energy is high enough to expand the bullet easily. This is also why bullets can come apart prematurely at high impact velocities and light construction. Copper is much harder than lead and the reason used in varying degrees of thickness to control how much a bullet deforms. This is also why mono bullets do not deform as much as lead/copper jacket bullets - they expand quickly due to high dynamic pressure at impact but due to being harder stop expanding at a higher velocity during penetration while a lead/copper bullet may keep expanding down the shank or come apart totally. In either case the full deformation happens very quickly once it starts and done in first several inches after which the bullet / pieces go on in whatever their terminal shape is.

Lou

I understand you're making the distinction that the hardness, or even state of matter of the target effects how the bullet will react, but in this thread I think it's safe to say we're discussing shooting game animals. Correct?

So if the dynamic pressure increases with the square of velocity, then doesn't velocity become the key determining factor in whether a given bullet will upset?

Less sciency, but I like to think of it as "is that Elk going to smack the front of my bullet hard enough to change the bullet's shape into an effective killing tool?"

That really has nothing to do with the energy of the bullet, but with the impact speed between the bullet and the elk and the construction of the bullet.

 

[Lou270]

I understand you're making the distinction that the hardness, or even state of matter of the target effects how the bullet will react, but in this thread I think it's safe to say we're discussing shooting game animals. Correct?

So if the dynamic pressure increases with the square of velocity, then doesn't velocity become the key determining factor in whether a given bullet will upset?

Less sciency, but I like to think of it as "is that Elk going to smack the front of my bullet hard enough to change the bullet's shape into an effective killing tool?"

That really has nothing to do with the energy of the bullet, but with the impact speed between the bullet and the elk and the construction of the bullet.

Think of it this way. Energy does the work. Velocity, bullet construction, material density affect rate of energy transfer. Rate of energy transfer does the wounding. The bigger the energy the bigger the amount of work that can be done. The faster the transfer the wider and shallower the damage. Bullet construction for different purposes is generally done to control the rate of energy transfer for some purpose

Lou

 

[sveltri]

Think of it this way. Energy does the work. Velocity, bullet construction, material density affect rate of energy transfer. Rate of energy transfer does the wounding. The bigger the energy the bigger the amount of work that can be done. The faster the transfer the wider and shallower the damage. Bullet construction for different purposes is generally done to control the rate of energy transfer for some purpose

Lou

Rate of energy transfer does the killing or sharp edges and fragments cutting tissue does the killing?

 

[Lou270]

Rate of energy transfer does the killing or sharp edges and fragments cutting tissue does the killing?

The work done destroying tissue by sharp edges and fragments does the killing. The rate of energy transfer from the bullet is what provided this energy to do this work. If the rate of energy transfer is slower this infers the bullet did not fragment or maybe expand at all

Lou

 

[General RE LEE]

So if a bullet has a lot of energy, let's say 1K fpe, but inadequate velocity, does it just slug through with no expansion?

I'm thinking of the 178 grain ELD-X out of 308. It dips below 1800 FPS at 450 yards for my load, but stays above 1K fpe till 600 yards.

So I guess 450 yards is my cap because that's the 1800 FPS threshold. I guess anything beyond that is a non expandable projectile with a lot of energy.

 

[Pharmseller]

Assuming proper bullet construction, placement is always #1. Velocity is #2.

There is no #3.





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