Questions about the irrelevance of energy (ft-lbs)

[HornPorn]

The idea that a .223 is just as good as a 300 win mag to hunt big game, is asinine. Will it kill it, yeah, sure. Is that really what a sportsman and someone who supposedly cares about game wants though, just to kill it? I like giving animals a quick death and minimal suffering.

If you can't be accurate with a real man's rifle, that's fine. No need to come up with all this fanfare to somehow suggest that what you are doing is somehow better or smarter though. It's laughable and is right there with skinny jeans, IPAs, and balsamic drizzles.

 

[Bugger]

I remember reading in another thread that a mere 10 ft-lbs. of recoil from a .243 Win. causes enough force on the head/neck of an 80 lb. child to approach TBI levels.

The only way a 243 is causing a TBI is if they’re holding it backwards.

 

[Skydog]

Why are you comparing that?

Because they use the same unit of measure (ft-lbs)...so it seems like there would be some equivalency. 10 ft-lbs of energy can cause the quick snap/jerk of a child's head to the point of causing TBI, or cause a larger tear in my rotator cuff, etc. Let's assume that a .243 NBT only "dumps" 50% of its energy in the deer. That's still 850 ft-lbs of energy, or 840 more ft-lbs than what it takes to cause TBI in a child. It just seems inconsistent to say that 10 ft-lbs of energy can cause serious injury/trauma to the human body, but 850 ft-lbs will do nothing on a deer.

Here’s a question you should answer. Which would you rather get shot with?

A solid caliber that doesn’t expand or a highly fragmenting bullet? For these purposes, you can assume the velocity is 2000 feet a second and the copper bullet weighs twice as much as the highly fragmenting bullet.

I'd much rather be shot with the solid one that doesn't expand. I understand that part of the argument.

 

[TaperPin]

I'm a recent convert (at least in theory) to the concept of using smaller calibers with light fragmenting bullets on big game. So, bear with me if these are dumb questions. I'm still having to work through and unlearn some previously held beliefs about "knockdown power".

I have read pages and pages of threads here at RS and I feel like I have a pretty good grasp on the concept, but...

I have read many comments stating things like "energy is a totally irrelevant/meaningless metric in terminal performance or effectiveness on game", the "myth of energy", etc.

However, I also see comments from advocates of the small caliber/fragmenting bullet school, that state things like "you don't want the bullet to exit because you want the full energy dump inside the animal and not on the dirt behind the animal" when discussing penetration. Statements like these seem to imply that there is some significance/benefit to having more energy transfer to the animal, otherwise why would one care if some of that energy is lost due to over-penetration/exit?

How do you square the idea of energy being totally irrelevant with also claiming the advantages of a full energy dump from the bullet? This seems inconsistent and contradictory. If energy is really irrelevant, why do I care if some of a bullet's energy is "wasted" on the dirt after exiting the animal? How is energy wasted if it is irrelevant to begin with? And why is more of an energy dump better than less of an energy dump if energy is truly irrelevant?

All other things being equal, is there or is there not an advantage of a 1500 ft-lb "dump of energy" versus a 1200 ft-lb "dump of energy"?

Hope my questions make sense...

It can help to think of any measure as an attempt to quantify what’s going on in the process of killing an animal. There are many different ways to kill - small fragmenting bullets can do it, but not all small fragmenting bullets. Traditional size and velocity bullets that do not fragment significantly have killed at least two million animals a year in North America, year in and year out - they work and foot pounds works as a measure for those traditional bullets. Both are correct in their corner of the world.

What confuses things are people who take the idea to the extreme and start claiming small cartridges are more deadly than large cartridges, and a misunderstanding that foot pounds of energy is quite literally the definition of the ability to do work. Small cartridge folks really mean to say their bullets can do enough work to kill effectively at a lower energy requirement. They will howl at this idea, but that’s physics, and physics isn’t going to change because these dudes on some internet site love 223s. Big cartridges aren’t getting the job done with efficiency like a Toyota Prius, but more like a full size 3/4 ton truck.

The aversion to any kind of recoil is somewhat of a head scratcher, but keep in mind many shooters aren’t shooting a lot and flinching is a problem with low volume shooters. Many 223 shooters flinch plenty. Many shooters today also aren’t exposed to a wide variety of different cartridges - I often hear the choice in recoil levels being very black and white, rather than a progression as cartridge size increases. When someone says they started with a big cartridge then switched to a small one, that’s ass backwards. Start small and work up if you want.

 

[Skydog]

Energy transfer of a bullet to an animal's anatomy is NOT simple or consistent enough to draw conclusions.

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.

And, even accounting for inconsistencies in calculating the energy transfer to the animal...let's assume it's very low...say only 25% of the energy gets "dumped" into the deer...that's still 340 ft-lbs of energy or 34 times the amount of energy it takes to cause TBI in a child or damage to a human shoulder.

 

[Bugger]

These points have been brought up so many times. If foot pounds mattered on their own then Mike Tyson could kill an elk with a punch and no animal on the planet should survive a car impact.

1

Thread 'Does Energy have the potential to affect terminal performance?'

Dec 26, 2023

I’ve heard this loosely parroted a few time across the web. “Energy is a useless number in terminal performance”. Is this a factual statement? Has the science been settled? Can its potential effect be so quickly deemed useless? Perhaps it is more misunderstood or unknown?

The purpose of this post:

1. A lively debate to the questions above.

2. To not spread possible misinformation either way on the matter, and to increase the knowledge base of this community. We know, we don’t know etc.

3. Come to some consensus through logical debate.

A few statements that we can hopefully agree...

• 10E
• Replies: 124
• Forum: Firearms

 

[Skydog]

If you can't be accurate with a real man's rifle, that's fine. No need to come up with all this fanfare to somehow suggest that what you are doing is somehow better or smarter though.

I'm not sure if this is directed specifically at me or to all the small caliber/RS folks in general, but my transition to a smaller caliber (less recoil) has been forced on me due to health issues and guidance from my doctors. It has nothing to do with not being able to handle a "real man's rifle", whatever that is.

 

[Skydog]

If foot pounds mattered on their own

Where have I claimed that they matter on their own? I'm confident that velocity, expansion, fragmentation, permanent wound channel, etc. matter more than foot pounds. I guess I'm just not fully convinced that foot pounds don't matter at all and that they are absolutely irrelevant.

Why can't it both/and instead of either/or?

ETA: Is the small caliber/fragmenting bullet argument totally dependent on holding to the premise that "energy is totally irrelevant"? Does the entire argument somehow fall apart if one concedes that energy may also play a part in causing trauma to a deer?

 

[Shortschaf]

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.

And, even accounting for inconsistencies in calculating the energy transfer to the animal...let's assume it's very low...say only 25% of the energy gets "dumped" into the deer...that's still 340 ft-lbs of energy or 34 times the amount of energy it takes to cause TBI in a child or damage to a human

You say you read the threads, but your questions imply that you did not actually read the threads. Go read them

This topic is so settled that even Ron Spomer gets it

Killing the Energy-Killing Myth — Ron Spomer Outdoors

I read a recent “Best Cartridges To Hunt Elk” blog that advised, and I paraphrase, “Most effective elk cartridges need to be flat-shooting and hit with enough energy to effectively dispatch a big bull.” And that’s a lot of bull. Because energy doesn’t kill.

www.ronspomeroutdoors.com

 

[Skydog]

Go read them

Can you be more specific?

 

[Shortschaf]

Can you be more specific?

Honestly the Ron Spomer link is probably a better start than any online forum thread. Its quick and direct without too much noise

It directly discusses recoil vs tissue damage and "total energy absorption" vs lethal shots

For the record I knew nothing about his article prior to this. I just googled "does energy matter in hunting" and it was the top result that was too ironic not to share

 

[hereinaz]

Because they use the same unit of measure (ft-lbs)...so it seems like there would be some equivalency. 10 ft-lbs of energy can cause the quick snap/jerk of a child's head to the point of causing TBI, or cause a larger tear in my rotator cuff, etc. Let's assume that a .243 NBT only "dumps" 50% of its energy in the deer. That's still 850 ft-lbs of energy, or 840 more ft-lbs than what it takes to cause TBI in a child. It just seems inconsistent to say that 10 ft-lbs of energy can cause serious injury/trauma to the human body, but 850 ft-lbs will do nothing on a deer.

I'd much rather be shot with the solid one that doesn't expand. I understand that part of the argument.

You are over complicating it. That’s the end of it.

The only thing that matters is tissue damage. Energy doesn’t tell you anything useful. That’s why you didn’t even need to know energy to make the decision to be shot by a solid non expanding bullet even though it weighed twice as much.

The mechanism of “injury” between being shot and “whiplash” are totally different so it makes no sense to compare them.

 

[Skydog]

Honestly the Ron Spomer link is probably a better start than any online forum thread. Its quick and direct without too much noise

It directly discusses recoil vs tissue damage and "total energy absorption" vs lethal shots

For the record I knew nothing about his article prior to this. I just googled "does energy matter in hunting" and it was the top result that was too ironic not to share

Thank you. I actually just finished reading it and it was helpful. But...two responses to the article:

1) Spomer says: "The quantity of energy in a bullet sent toward your game is the same as the energy sent back into the rifle — and your shoulder behind that rifle. So, if the energy in the recoiling rifle didn’t instantly kill you, how can the energy in the bullet instantly kill your target animal of the same or larger size? You absorbed all that energy. Why aren’t you dead?" ...This is false/misleading. The recoil energy of a .243 against my shoulder is only 10 ft-lbs. The energy of the 95 gr NBT at an impact of 100 yards is 1700 ft-lbs (or 340 ft-lbs if we assume that only 25% gets transferred to the animal, and there's no valid reason to assume that it is only 25%). My shoulder is not absorbing 340 -1700 ft-lbs of energy, it's only absorbing 10 ft-lbs. However, the deer is absorbing 340-1700 ft-lbs of energy. That's a huge difference...right?

2) Even the article concedes that energy matters, even if it only matters a little.

A couple of quotes from the article...

"The bullet stayed inside, too, so the little coyote absorbed all that killing-energy."

"Honestly, bullet energy matters. A little. Our problem is conceptual."

I haven't claimed any more than this. I've never said energy alone matters, or energy matters a lot more than velocity, etc. I've simply questioned the accuracy of the claim that energy is irrelevant. And I'm not sure why that claim has to be so zealously defended. And I don't see how the case for small calibers rises or falls on defending that claim.

 

[hereinaz]

Where have I claimed that they matter on their own? I'm confident that velocity, expansion, fragmentation, permanent wound channel, etc. matter more than foot pounds. I guess I'm just not fully convinced that foot pounds don't matter at all and that they are absolutely irrelevant.

Why can't it both/and instead of either/or?

ETA: Is the small caliber/fragmenting bullet argument totally dependent on holding to the premise that "energy is totally irrelevant"? Does the entire argument somehow fall apart if one concedes that energy may also play a part in causing trauma to a deer?

If you want to make it matter and include energy in the calculations, then you can absolutely create complex ways to analyze bullet effect and categorize by energy.

Does it resolve it if I were to say, sure, energy matters, but it is so hard to calculate anything using energy that we say it doesn’t matter and use the easiest factors to compare?

At the end of the day, energy is a scientific concept. It is calculated off velocity and mass. Energy doesn’t apply effectively or simply to help a person understand the measure of wounding. It has been a “smarty pants” way the gun writers and Fudds have used it kinda like “wallop”.

If you want to “make it matter” in a discussion you will have to describe a very complex scientific formula, and set parameters for each bullet type and distinguish them. Even then, you will find that “energy” is not very helpful in the calculation.

If you think it should matter or don’t know if it matters, try to gather the data necessary to start making calculations where energy as expressed in foot pounds matter.

You show everyone else why it matters if you feel it does. I have a feeling you will quickly come to understand that “energy” isn’t an easy way to describe it. Which is why we say “it doesn’t matter”.

What you will find has a much larger effect in the analysis is impact velocity and bullet design. With those two factors, you can more easily describe the effect.

If energy were useful as a metric, or easy to quantify, then you or someone else would have to explained it.

In Arizona, the inside of a car gets blazing hot. The color of the car has an effect, sure, but all of them are gonna burn your butt when you get in. You won’t be able to tell the difference between a black seat or a tan seat—so we say, it doesn’t matter if you buy a white car or not…

Back to ballistics, double the weight of the bullet and get maybe 2-4 inches more penetration if other factors remain the same. And, even if you double the volume of permanent wound channel, you only increase the diameter of the wound channel by a much smaller fraction.

Here is the exit question:

Once you put a small football sized wound channel 4-6 inches in diameter with a .223 fragmenting bullet that penetrates at least 13-16 inches through the vitals—-does it really matter if you use a 7mm bullet and make a football 6-8 inches in diameter and total penetration of 16-20”?

You keep asking the same question: why do you guys say energy matter?

If this doesn’t convince or satisfy you, just accept that “it doesn’t matter to us” whether the car is black or white. It can matter to you and that’s ok.

 

[Skydog]

Just for fun...I asked Grok AI...apparently Grok didn't scan the RS forum for content when researching an answer.

Per Grok AI:

When evaluating a bullet's effectiveness on deer, both velocity (measured in feet per second, fps) and energy (measured in foot-pounds, ft-lbs) play important roles, but their significance depends on context. Let’s break it down:

Velocity (fps)​

• What it does: Velocity determines how fast the bullet travels, affecting its trajectory, time to target, and expansion upon impact. Higher velocity can enhance terminal performance, especially for bullets designed to expand (e.g., hollow points or soft points), as they often require a minimum speed to mushroom effectively.
• Relevance to deer: For deer-sized game (typically 100-300 lbs), bullets need enough velocity to penetrate hide, muscle, and bone while expanding to create a sufficient wound channel. Most hunting rounds for deer (e.g., .308 Winchester, .30-06 Springfield) deliver velocities between 2,000-3,000 fps at the muzzle, which is adequate for reliable expansion and penetration out to typical hunting ranges (100-300 yards).
• Limitations: Velocity alone doesn’t tell the whole story. A super-fast, lightweight bullet might lack the mass to penetrate deeply, potentially leading to shallow wounds that fail to reach vital organs.

Energy (ft-lbs)​

• What it does: Energy represents the bullet’s capacity to do work—think of it as the "punch" it delivers. It’s calculated as Energy=12×mass×velocity2 \text{Energy} = \frac{1}{2} \times \text{mass} \times \text{velocity}^2 Energy=21×mass×velocity2, so it combines bullet weight and speed. Higher energy generally correlates with greater tissue damage and penetration potential.
• Relevance to deer: Experts often recommend a minimum of 1,000 ft-lbs of energy at impact for clean, ethical kills on deer. This ensures the bullet can break through bone (e.g., a shoulder) and disrupt vital organs. For example, a .30-06 with a 150-grain bullet might start with 2,800 ft-lbs at the muzzle and retain 1,500 ft-lbs at 200 yards—plenty for deer.
• Limitations: Raw energy doesn’t account for bullet construction or shot placement. A high-energy bullet that over-penetrates or fails to expand might waste energy beyond the target, reducing effectiveness.

Which is More Important?​

For deer hunting, energy is generally the more critical metric because it better reflects the bullet’s ability to deliver lethal damage through penetration and tissue disruption. However, velocity is a key enabler—it drives energy and ensures proper bullet performance (expansion or fragmentation).

Practical Considerations:​

1. Bullet Design: A well-constructed bullet (e.g., bonded or controlled-expansion types like Nosler Partition or Barnes TTSX) can maximize the effectiveness of both metrics. Expansion relies on velocity, while penetration relies on energy and mass.
2. Range: At longer distances, velocity drops faster than energy (due to the squared term in the energy equation), so energy retention becomes a better indicator of performance downrange.
3. Shot Placement: Neither metric matters if you miss the vitals (heart, lungs, or major arteries). A 1,200 ft-lbs bullet through the lungs is far more effective than a 2,000 ft-lbs bullet through the guts.

Rule of Thumb​

• Minimums for Deer: Aim for 1,000-1,500 ft-lbs of energy and 1,800-2,000 fps at the point of impact. Most common deer calibers (.270 Win, .308 Win, .30-06, etc.) exceed these thresholds within 200-300 yards when paired with 130-180 grain bullets.
• Priority: Focus on energy as the primary benchmark, but ensure velocity supports the bullet’s terminal performance.

So, while both are important, energy edges out as the more decisive factor for evaluating effectiveness on deer—assuming velocity is sufficient to get the job done.

 

[Marbles]

I remember reading in another thread that a mere 10 ft-lbs. of recoil from a .243 Win. causes enough force on the head/neck of an 80 lb. child to approach TBI levels. I've also been told by my doctors/surgeon that I need to minimize recoil to avoid further injury to my neck/shoulder.

So...I'm still trying to wrap my head around how 10 ft-lbs of energy can cause TBI in an 80 lb. child, create issues for my cervical fusion, cause further damage to my shoulder joint/rotator cuff, etc...but 1700 ft-lbs of energy on an 80 lb. deer is irrelevant.

You are confusing things. The first problem is saying "energy" rather than KE, momentum, pressure, acceleration, velocity. All are forms of energy, but they are not the same.

This is like asking what's heavier, a pound of feathers or a pound of nails. What weighs more, fat or muscle. The question is wrong so you cannot get an answer that is meaningful, but many people will give an answer that is flat wrong and think they understand the concept. It is all fine, until you try to apply the "knowledge".

No two units metric like ft.lb describes the issue with recoil. Now, you get to ft.lb/s, but that is not actually used, instead it is lb.ft/s and you start getting somewhere, but that is no longer a unit of KE.

Using that unit, a 9 lb 7 PRC shooting the example I used above for KE is making 115 lb.ft/s. However, the bullet is only carrying 75 lb.ft/s. Recoil KE is 23.0 ft.lbs for a bullet KE over 3000.

A 7 lb 243 shooting the example I used above is making 72 lb.ft/s. The bullet is carrying 44 lb.ft/s. Recoil KE is 11.6 ft.lbs.

Neither of those bullets hitting your shoulder will case a TBI in an 80 pound kid, but the KE is significantly higher than either rifles. Why do you think that is?

Now, for every force there is an equal and opposite reaction, the difference in bullet KE and rifle KE or bullet momentum and rifle momentum should be enough to tell you the actual interaction is far more complex than the KE or momentum value and that is before we move beyond just the rifle.

I'm not good enough at physics to get much deeper with any confidence. But, unless you are, you will not find a clear answer to what you ask.

In the end theory always bows to reality.

Note, I am not saying KE doesn't matter, only that it is one of the more useless things in predicting performance, to the extent that most people might as well be talking about magic when they bring it up. Thus, while it technicall matters, it is effectively meaningless.

 

[Shortschaf]

Just for fun...I asked Grok AI...apparently Grok didn't scan the RS forum for content when researching an answer.

Per Grok AI:

When evaluating a bullet's effectiveness on deer, both velocity (measured in feet per second, fps) and energy (measured in foot-pounds, ft-lbs) play important roles, but their significance depends on context. Let’s break it down:

Velocity (fps)​

• What it does: Velocity determines how fast the bullet travels, affecting its trajectory, time to target, and expansion upon impact. Higher velocity can enhance terminal performance, especially for bullets designed to expand (e.g., hollow points or soft points), as they often require a minimum speed to mushroom effectively.
• Relevance to deer: For deer-sized game (typically 100-300 lbs), bullets need enough velocity to penetrate hide, muscle, and bone while expanding to create a sufficient wound channel. Most hunting rounds for deer (e.g., .308 Winchester, .30-06 Springfield) deliver velocities between 2,000-3,000 fps at the muzzle, which is adequate for reliable expansion and penetration out to typical hunting ranges (100-300 yards).
• Limitations: Velocity alone doesn’t tell the whole story. A super-fast, lightweight bullet might lack the mass to penetrate deeply, potentially leading to shallow wounds that fail to reach vital organs.

Energy (ft-lbs)​

• What it does: Energy represents the bullet’s capacity to do work—think of it as the "punch" it delivers. It’s calculated as Energy=12×mass×velocity2 \text{Energy} = \frac{1}{2} \times \text{mass} \times \text{velocity}^2 Energy=21×mass×velocity2, so it combines bullet weight and speed. Higher energy generally correlates with greater tissue damage and penetration potential.
• Relevance to deer: Experts often recommend a minimum of 1,000 ft-lbs of energy at impact for clean, ethical kills on deer. This ensures the bullet can break through bone (e.g., a shoulder) and disrupt vital organs. For example, a .30-06 with a 150-grain bullet might start with 2,800 ft-lbs at the muzzle and retain 1,500 ft-lbs at 200 yards—plenty for deer.
• Limitations: Raw energy doesn’t account for bullet construction or shot placement. A high-energy bullet that over-penetrates or fails to expand might waste energy beyond the target, reducing effectiveness.

Which is More Important?​

For deer hunting, energy is generally the more critical metric because it better reflects the bullet’s ability to deliver lethal damage through penetration and tissue disruption. However, velocity is a key enabler—it drives energy and ensures proper bullet performance (expansion or fragmentation).

Practical Considerations:​

1. Bullet Design: A well-constructed bullet (e.g., bonded or controlled-expansion types like Nosler Partition or Barnes TTSX) can maximize the effectiveness of both metrics. Expansion relies on velocity, while penetration relies on energy and mass.
2. Range: At longer distances, velocity drops faster than energy (due to the squared term in the energy equation), so energy retention becomes a better indicator of performance downrange.
3. Shot Placement: Neither metric matters if you miss the vitals (heart, lungs, or major arteries). A 1,200 ft-lbs bullet through the lungs is far more effective than a 2,000 ft-lbs bullet through the guts.

Rule of Thumb​

• Minimums for Deer: Aim for 1,000-1,500 ft-lbs of energy and 1,800-2,000 fps at the point of impact. Most common deer calibers (.270 Win, .308 Win, .30-06, etc.) exceed these thresholds within 200-300 yards when paired with 130-180 grain bullets.
• Priority: Focus on energy as the primary benchmark, but ensure velocity supports the bullet’s terminal performance.

So, while both are important, energy edges out as the more decisive factor for evaluating effectiveness on deer—assuming velocity is sufficient to get the job done.

This was about as helpful as tits on a bull

 

[hereinaz]

Just for fun...I asked Grok AI...apparently Grok didn't scan the RS forum for content when researching an answer.

Per Grok AI:

When evaluating a bullet's effectiveness on deer, both velocity (measured in feet per second, fps) and energy (measured in foot-pounds, ft-lbs) play important roles, but their significance depends on context. Let’s break it down:

Velocity (fps)​

• What it does: Velocity determines how fast the bullet travels, affecting its trajectory, time to target, and expansion upon impact. Higher velocity can enhance terminal performance, especially for bullets designed to expand (e.g., hollow points or soft points), as they often require a minimum speed to mushroom effectively.
• Relevance to deer: For deer-sized game (typically 100-300 lbs), bullets need enough velocity to penetrate hide, muscle, and bone while expanding to create a sufficient wound channel. Most hunting rounds for deer (e.g., .308 Winchester, .30-06 Springfield) deliver velocities between 2,000-3,000 fps at the muzzle, which is adequate for reliable expansion and penetration out to typical hunting ranges (100-300 yards).
• Limitations: Velocity alone doesn’t tell the whole story. A super-fast, lightweight bullet might lack the mass to penetrate deeply, potentially leading to shallow wounds that fail to reach vital organs.

Energy (ft-lbs)​

• What it does: Energy represents the bullet’s capacity to do work—think of it as the "punch" it delivers. It’s calculated as Energy=12×mass×velocity2 \text{Energy} = \frac{1}{2} \times \text{mass} \times \text{velocity}^2 Energy=21×mass×velocity2, so it combines bullet weight and speed. Higher energy generally correlates with greater tissue damage and penetration potential.
• Relevance to deer: Experts often recommend a minimum of 1,000 ft-lbs of energy at impact for clean, ethical kills on deer. This ensures the bullet can break through bone (e.g., a shoulder) and disrupt vital organs. For example, a .30-06 with a 150-grain bullet might start with 2,800 ft-lbs at the muzzle and retain 1,500 ft-lbs at 200 yards—plenty for deer.
• Limitations: Raw energy doesn’t account for bullet construction or shot placement. A high-energy bullet that over-penetrates or fails to expand might waste energy beyond the target, reducing effectiveness.

Which is More Important?​

For deer hunting, energy is generally the more critical metric because it better reflects the bullet’s ability to deliver lethal damage through penetration and tissue disruption. However, velocity is a key enabler—it drives energy and ensures proper bullet performance (expansion or fragmentation).

Practical Considerations:​

1. Bullet Design: A well-constructed bullet (e.g., bonded or controlled-expansion types like Nosler Partition or Barnes TTSX) can maximize the effectiveness of both metrics. Expansion relies on velocity, while penetration relies on energy and mass.
2. Range: At longer distances, velocity drops faster than energy (due to the squared term in the energy equation), so energy retention becomes a better indicator of performance downrange.
3. Shot Placement: Neither metric matters if you miss the vitals (heart, lungs, or major arteries). A 1,200 ft-lbs bullet through the lungs is far more effective than a 2,000 ft-lbs bullet through the guts.

Rule of Thumb​

• Minimums for Deer: Aim for 1,000-1,500 ft-lbs of energy and 1,800-2,000 fps at the point of impact. Most common deer calibers (.270 Win, .308 Win, .30-06, etc.) exceed these thresholds within 200-300 yards when paired with 130-180 grain bullets.
• Priority: Focus on energy as the primary benchmark, but ensure velocity supports the bullet’s terminal performance.

So, while both are important, energy edges out as the more decisive factor for evaluating effectiveness on deer—assuming velocity is sufficient to get the job done.

It’s because AI trains on existing garbage, it doesn’t actually think on its own. Garbage in and Garbage out.

And, Grok does not access Rokslide at all, unless I am mistaken.

It’s not really “intelligence” as much as it is a fast computer that can take what is written and then summarize it.

Technically, they are “LLM” not “AI” if you get down to it.

Large Language Model

 

[Skydog]

This was about as helpful as tits on a bull

It’s because AI trains on existing garbage, it doesn’t actually think on its own. Garbage in and Garbage out.

And, Grok does not access Rokslide at all, unless I am mistaken.

It’s not really “intelligence” as much as it is a fast computer that can take what is written and then summarize it.

Technically, they are “LLM” not “AI” if you get down to it.

Large Language Model

Understood. I work with AI/LLM at my job. That's why I said it was "just for fun".

 

[hereinaz]

I haven't claimed any more than this. I've never said energy alone matters, or energy matters a lot more than velocity, etc. I've simply questioned the accuracy of the claim that energy is irrelevant. And I'm not sure why that claim has to be so zealously defended. And I don't see how the case for small calibers rises or falls on defending that claim.

You haven’t explained in a coherent way why foot pounds of “energy” matters to the discussion.

And, the “zealous defense” of the claim really is a reaction to the fudds who say “you need 1500 foot pounds to ethically kill an elk.”

In THAT conversation and context, energy is irrelevant to ethically killing an elk.

I thought there may have been some greater point to the discussion, but this wasn’t about much more than you picking at the “zealously defended” claim of something. It’s a rhetoric trick to create the absolute position and then pick at it with “I have questioned the claim that energy is irrelevant”.