Questions about the irrelevance of energy (ft-lbs)

[Marbles]

When people say energy (m*v squared) doesn’t matter do they realize a bullet without velocity sits on the shelf and a bullet without mass doesn’t exist? I’m a little tongue in cheek but I can’t help it.

And do people who argue energy matters realize that 92,000 ft.lb of energy is quite easy to survive, as someone that has been hit by that, I know it for a fact. It doesn't hurt at all

Anyway, this and Grok confirm this conversation is pointless to continue.








46000 lb fire engine going about 2 feet per second (less than 1 mph).

 

[Bluumoon]

Not enough information to determine that.

Same bullet different impact velocity or different bullets?

Point is the #s don’t matter, what happens in tissue does.

 

[rickyw]

And do people who argue energy matters realize that 92,000 ft.lb of energy is quite easy to survive, as someone that has been hit by that, I know it for a fact. It doesn't hurt at all

Anyway, this and Grok confirm this conversation is pointless to continue.








46000 lb fire engine going about 2 feet per second (less than 1 mph).

It’s all about context isn’t it? all I was trying to say is that some mass and some velocity is needed for a bullet to work

 

[Skydog]

That is, in essence, the point.

The message of the "energy is a useless metric" crowd is, the energy number doesn't really correlate with wound channel characteristics or killing capability. You can have low KE options like a 77TMK or 108 ELDM that consistently produce wide, deep permanent wound channels. You can have high KE options like a 225 CX or 210 TTSX (or FMJ) at low-ish velocity that will poke a very narrow hole pretty deep, resulting in a long time to incapacitation.

108 Berger and 215 Berger will produce wound channels that are more alike than different if both are at same velocity (call it 2400 fps, right in the sweet spot for both). The 215 will be a bit deeper and a bit wider, probably 5" wide vs 6-7" wide, and 18-20 vs 24ish deep but broadly speaking that same football shaped cavity of shredded tissue. It might be double the cubic inches of shredded tissue, but both are more than adequate to quickly kill an elk and you're only gaining a little bit of lateral margin for error (like you can be an inch and a half further off and still have the edge of the cavity reach the same place).

They will be very different if they are at the same energy. At 1000 ft-lb, the 215 is around 1400 fps, well below the point where upset gets unreliable. Very good chance that we have a .308ish diameter column of destroyed tissue. The 108 is doing 2050ish, and will upset reliably, producing a football shaped cavity of shredded tissue.

Even given like bullet construction, energy doesn't correlate with wound characteristics nearly as well as impact velocity.

So if same energy doesn't correlate with like bullet weights but different construction (FMJ unacceptable wound channel, mono/hard bonded is narrow but deep, Berger/ELD type very wide but maybe not as deep), doesn't correlate with like construction but different weight, what is it actually correlated with?

If you have the pieces of information that let you say something meaningful about how the energy gets applied, you already have way more specific information than what the energy number might convey.

Without knowing construction and impact velocity, energy is a useless metric. Without knowing energy value, construction and impact velocity can tell you a lot about the characteristics of the wound.

This was helpful in getting it through my thick skull. Thank you!

 

[Skydog]

So, to bring this back full circle...how would you "energy is useless" folks respond to the claim that it's better to not have a bullet pass through because you don't want to waste energy on the dirt behind the animal, you want a full energy dump in the animal, etc.?

Or...to make this more practical, and less academic...in your experience, does a bullet that remains in the animal incapacitate/kill faster than one that exits. Forget whether it has anything to do with energy or not. Regardless of the cause/why, does a bullet that doesn't exit usually kill better/faster?

 

[Bluumoon]

So, to bring this back full circle...how would you "energy is useless" folks respond to the claim that it's better to not have a bullet pass through because you don't want to waste energy on the dirt behind the animal, you want a full energy dump in the animal, etc.?

Or...to make this more practical, and less academic...in your experience, does a bullet that remains in the animal incapacitate/kill faster than one that exits. Forget whether it has anything to do with energy or not. Regardless of the cause/why, does a bullet that doesn't exit kill better/faster?

What type of bullet and corresponding wound channel do you suspect exits more?

 

[Skydog]

What type of bullet and corresponding wound channel do you suspect exits more?

I would suspect that both a solid copper and a bonded bullet would have a greater chance of exiting than something like a NBT or ELD-X/M. And I suspect the latter would create a larger permanent wound channel, more tissue tearing, etc..

And I see where this is going...

 

[Macintosh]

Anyone ever bungee jump? Or seen a video of it?
Someone jumps off a bridge and accelerates at 9.8m per second, per second, for hundreds of feet. Their mass x their velocity equals a lot of “energy”. Yet the persons reaction on impact is a lot closer to “giggling” than it is to “splattering”.

Now repeat the EXACT same exercise, but instead of a bungee cord, use a steel cable. Rather than a giggle, the result is broken bones, ruptured internal organs, and broken equipment…now we’re dealing with a splatter, not a giggle. Yet the ENERGY is precisely the same. The difference is only that the energy was applied much slower in the case of the bungee, resulting in a far, far lower peak force, aka f-max. Deceleration TIME is a cushion, and tiny fractions of a second make an exponential difference.

It’s the bullet and how the bullet behaves on impact that APPLIES the energy. You can achieve a greater application using less total energy if you apply it more efficiently.

This is why energy isnt a predictor of damage—its only how that energy is APPLIED that matters with regard to predicting damage. Talking about total energy without also talking about how its applied simply doesn't tell you enough to predict whats going to happen.

 

[Bluumoon]

I would suspect that both a solid copper and a bonded bullet would have a greater chance of exiting than something like a NBT or ELD-X/M. And I suspect the latter would create a larger permanent wound channel, more tissue tearing, etc..

And I see where this is going...

I’m only parroting the info, so take it for what it’s worth. Form covers in the the Hunt Backcountry podcasts

That perfect mushroom w copper bullets increases the chance of it trampolining on off side hide. Low weight shank of ELDM (and the like) is smaller surface area and passes through off side hide easier.

 

[Bluefish]

If we can rely on manufacturers' data in their ballistics tables to estimate velocity at impact, why can't we also rely on the energy data in those same tables to provide us with energy at impact? You can't have it both ways.

I don’t think anyone is arguing the amount of ke isn’t there at impact. If the velocity is x and the weight is y the ke is 1/2xy^2. That’s a straight calculation.

the energy at impact = wounding is where it falls apart. To solve that you have to know what bullet is being used and if it will upset. The two extremes, a thin jacketed bullet (varmit) may just explode at impact dumping all the energy, yet not reach the vitals thus no death. A fmj or a bullet going too slow may just pencil through and retain almost all its energy and not kill the animal. What works best is a bullet that creates a 2-6” wound channel and penetrates 14+”. That ensures that the vitals are damaged and the brain is starved of oxygen and the animal dies.

 

[Skydog]

This is why energy isnt a predictor of damage

I think this is a better/clearer way to state this rather than just the blanket statement that "energy is irrelevant/meaningless".

 

[Macintosh]

Bottom line is 99% of what you read here is inexact language. Thats why it sometimes sounds contradictory, because the language used often isnt technically exact, even if the person saying it has the right idea.

But ultimately, if two cartridges both carry 1500 ftlb of energy….and one is an expanding bullet, and other is a fmj that is guaranteed to pencil…using the “energy” figure as a determinant of what is responsible and what isnt is pretty much meaningless, even if energy as a concept is certainly relevant.

 

[Skydog]

What works best is a bullet that creates a 2-6” wound channel and penetrates 14+”.

I think where it gets a little confusing - at least for me - is this...

Let's say we have two bullets. Both bullets create a 2-6” wound channel and both penetrate 14+". One of these bullets impacts at 1800 ft-lbs of energy and the other impacts at 1300 ft-lbs of energy. No difference?

 

[Skydog]

Bottom line is 99% of what you read here is inexact language. Thats why it sometimes sounds contradictory, because the language used often isnt technically exact, even if the person saying it has the right idea.

Amen, brother...this is what I was trying to get across in one of my previous posts...but you said it much simpler/better than I did.

 

[Macintosh]

No difference?

There is a academically-measurable difference in wound size assuming same bullet construction—given similar velocity and same bullet construction, the bigger one will make a bigger wound. The question is whether the difference has any benefit? If the smaller is plenty big to kill reliably and quickly…what is the benefit of a bigger hole? The folks saying there is “no difference” are not saying the two bullets will create the same sized hole, they are saying there is a point of diminishing returns, after which there is no further benefit to making the wound even larger. Dead=dead. “More dead” isnt a thing. Not everyone agrees with that, but thats what the statement is saying.

If youre asking about different bullets, where by virtue of construction a smaller bullet carrying less energy makes the exact same sized wound in the animal as a bullet carrying more energy…i think it would be splitting hairs to say if there is any measure able difference, but from the actual scientific papers on the topic Ive read as theyve come up here there is not a measurable difference in time to incapacitation.

 

[TaperPin]

I also get a laugh when anti-energy folks claim large cartridges with double bullet weight at the same velocity are bad, but shooting animals twice is normal (double the energy imparted into the animal).

When I first showed up it was fun to equate 223 energy at long range to the 22 hornet 400 yards closer. Guys flipped out, said bla, bla, bla, and then it sunk in for some folks how ridiculously anemic this combination is. It’s not the mastodon killer many would like you to believe. A good source of proof most small caliber guys don’t fully buy into it is the sheer number of cartridges larger than 223 that are shot.

I’m also getting a kick out of many of the 223 crowd gravitating to heavy bullets in 6mm, and now 25 caliber rounds. Those who kicked and screamed about energy not making a difference are shooting much more energy, but now it’s ok. *chuckle*

 

[Bluefish]

I think where it gets a little confusing - at least for me - is this...

Let's say we have two bullets. Both bullets create a 2-6” wound channel and both penetrate 14+". One of these bullets impacts at 1800 ft-lbs of energy and the other impacts at 1300 ft-lbs of energy. No difference?

There may be slight differences in wound channel size, but is there a difference in time to incapacitation? I don’t think there is one that can be directly linked to kinetic energy. Some of my quickest kills were with a low energy round less than 1000 ftlbs. The slowest were the highest energy at 3000+. It simply didn’t match up to what I had been told or read.

That’s what got me researching the whole concept of what actually incapacitates an animal. Also lead me to Rokslide. I still don’t hunt with a small caliber because it’s not legal where I hunt. Would I use a smaller caliber if I could, heck yeah.

 

[Formidilosus]

I think where it gets a little confusing - at least for me - is this...

Let's say we have two bullets. Both bullets create a 2-6” wound channel and both penetrate 14+". One of these bullets impacts at 1800 ft-lbs of energy and the other impacts at 1300 ft-lbs of energy. No difference?

You already stated they created the same wound- so no, there is no difference.


A 2” wide wound 14” deep- doesn’t matter what created it, the wound is what it is.

 

[hereinaz]

It was never my intent to do so. If you go back and read the OP, the intent was to try to resolve the apparent inconsistency/contradiction in these two statements:

1) Energy is completely irrelevant.
2) A complete pass through of the bullet is a bad thing because it wastes energy outside of the animal. In other words...more energy is desirable and it's more lethal if the animal absorbs more of the energy by keeping the bullet inside.

Those two statements are contradictory. If energy is irrelevant why worry about wasting/losing some of it?

OK. I have not made any statements about minimum ft-lb thresholds for killing deer, elk, or anything. So, that is not the conversation and context of this thread. And I may be somewhat of a Fudd, but I'm OK with that.


See the first response above in this post...again...I was picking on the apparent inconsistency in those two statements.

I never challenged the small caliber/fragmenting bullet concept. I even stated that I was converted due to the overwhelming amount of evidence presented on this site and planned on hunting with a small caliber/fragmenting bullet this fall. Did you even see/read those posts?

I think your comment here and your assumption about my true intent is a bit of an over-reaction to someone who has no qualm with you. I simply think that it is somewhat of an overstatement to claim that "energy is totally irrelevant". And it doesn't even help your case to do so. That's why I said I don't see how the argument for small calibers rises and falls with that claim. You can easily prove your case without taking that "absolute position" on energy. And taking that absolute position probably hurts your case with the Fudds rather than helps it. So, why defend it so zealously when it is not even a necessary premise of your argument. Hope that clarifies the point I was trying to make.

You also have to consider that there does not seem to be 100% consensus on the "energy is irrelevant" claim even within your own camp. Hence, some folks wanting those small caliber/fragmenting bullets to dump all their energy inside the animal and not waste any energy on the dirt outside the animal.

My apologies if I offended you.

Again, you miss the context where “people say it is irrelevant” is a reaction to those people who give energy as the minimum ethical without anything more. You can’t really separate it out for your “people say” argument.

In that case, the energy in foot pounds ACTUALLY IS IRRELEVANT. Context matters.

The context for the “energy dump” is there is no need for pass through if the bullet cusses sufficient damage. No need for a pass through to track an animal that has destroyed lungs/heart. So you don’t need to shoot more gun than necessary to avoid recoil.

They are mutually exclusive arguments in that sense.

On the extent “people say” crazy things, sure some might conflate it but I can’t explain crazy.

 

[Skydog]

You already stated they created the same wound- so no, there is no difference.


A 2” wide wound 14” deep- doesn’t matter what created it, the wound is what it is.

Yeah, I get it now...took a bit...but it makes sense now.