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Old January 25, 2017, 11:28 PM   #1
TheFriendlyMarksman
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The energy gimmick

Most boxes of ammo now include not just trajectory data, but kinetic energy as well. The idea is that energy is a measure of killing power, but it isn't. A baseball has more energy than a small caliber handgun, and a football player at a dead run has more than a 357 magnum! Most of us wouldn't want to be hit by either a football player or a baseball, but neither would be fatal. Consider also that a FMJ bullet has the same kinetic energy as a hollow point, but the hollow point does much more damage. There are plenty of formulas that try to quantify stopping power, but the only real way to measure it is empirically. Tissue damage to vital organs, not kinetic energy, is what kills.
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Old January 26, 2017, 12:36 AM   #2
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Energy isn't a gimmick, it's a formula, E=mv^2
I think manufacturers put it on the boxes because it's one of the only things to go on as far as performance. There isn't a lot of real life practical data to reference besides ballistic gelatin tests, and as far as actual people go, the human body is so varied that the way one bullet preformed in situation A is not going to necessarily exhibit the same results in situation B.
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Old January 26, 2017, 12:57 AM   #3
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There isn't a lot of real life practical data to reference besides ballistic gelatin tests, and as far as actual people go, the human body is so varied that the way one bullet preformed in situation A is not going to necessarily exhibit the same results in situation B.
The human body is no more varied than big game animals...and the ammo companies have pretty well got consistent results there. For the most part, the same factors that work on big game animals...will work on humans....most notable of these will be...shot placement.
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Old January 26, 2017, 01:01 AM   #4
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it would be awesome if manufacturers put ballistic gelatin results on their boxes. But until then energy isn't irrelevant.... All other things equal Id rather buy the one with more energy, and I'm certainly not buying anything that doesn't list it at all.
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Old January 26, 2017, 02:41 AM   #5
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and I'm certainly not buying anything that doesn't list it at all.
Clearly, you didn't grow up shooting when I did.
back in the "stone age" ammo makers didn't put any velocity, trajectory, or energy information on the box. Caliber and bullet weight and usually bullet type was it. (along with the boilerplate "use only in..." type info).

To find out velocity, trajectory and energy, one had to go to a printed table (websites were where spiders caught their food), in the maker's catalogue, or in books such as Shooter's Bible or Gun Digest, or in reloading manuals.

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Tissue damage to vital organs, not kinetic energy, is what kills.
Sure, but the damage doesn't occur without kinetic energy. We use KE (in ft/lbs or what ever units you use) not because there is any direct formula equating energy to "killing power", but because it is about the ONLY thing all rounds and shootings have in common.

It's for comparison between rounds, a general, not an specific accurate performance predictor.

Like ballistic gelatin, it gives us a uniform standard for comparison of potential, not actual results.

Energy is a straight mathematical computation, and does not address ANY of the other factors that determine how effective a given round will be.
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Old January 26, 2017, 04:59 AM   #6
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Kinetic energy is proportionate to the square of velocity, while it is only directly proportionate to mass.

So, small changes in velocity make a big difference in the amount of energy. Much bigger than changing the weight.

So, it's possible to end up with outrageous amounts of energy by firing a a lightweight (for caliber) projectile at a relatively high velocity. Large amounts of energy make for impressive advertisements.

The problem is that such bullets tend to disintegrate and offer very poor penetration. Energy isn't the whole story.

Because of this, I would even regard a statement of energy as a point of suspicion, and especially if it's used as a primary selling point.

If I were going to pin a number on stopping ability, I think momentum is generally more relevant. The problem is that a chart of similar numbers makes for unintertesting advertisements.
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Old January 26, 2017, 07:53 AM   #7
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It's for comparison between rounds, a general, not an specific accurate performance predictor.

Like ballistic gelatin, it gives us a uniform standard for comparison of potential, not actual results.
+1 Well-put.
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Old January 26, 2017, 08:51 AM   #8
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Most boxes of ammo now include not just trajectory data, but kinetic energy as well. The idea is that energy is a measure of killing power, but it isn't. A baseball has more energy than a small caliber handgun, and a football player at a dead run has more than a 357 magnum! Most of us wouldn't want to be hit by either a football player or a baseball, but neither would be fatal. Consider also that a FMJ bullet has the same kinetic energy as a hollow point, but the hollow point does much more damage. There are plenty of formulas that try to quantify stopping power, but the only real way to measure it is empirically. Tissue damage to vital organs, not kinetic energy, is what kills.
Following that logic, no information needs to be included on the box about bullet performance because none of them actually kill. The problem you are having with energy isn't with the information being provided on the box of ammo, but in how people interpret it, "the idea" as you called it. Nothing is implied by the providers of the information. It is all on the interpretation end.

No, energy is not a gimmick. It is simply information. How it is used is a whole other matter. If YOU don't like the information, then don't use it.
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Old January 26, 2017, 09:05 AM   #9
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As long as you are comparing bullets of similar size, weight and construction energy numbers are a pretty accurate way to predict effectiveness. There is nothing wrong with providing the data, but the user must be able to correctly interpret the data.
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Old January 26, 2017, 09:09 AM   #10
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Knowing barrel length of the test data would be helpful.
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Old January 26, 2017, 10:20 AM   #11
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I prefer to think about kinetic energy figures like the horsepower rating of a car; it's not very helpful without also knowing and understanding a bunch of other information. 240 hp in a Lotus Exige means a very different thing than 240 hp in a Ford F-350.

They're also comparable in that anyone who claims that it's the only important number is probably naive and/or completely obsessed with only one aspect of its performance.
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Old January 26, 2017, 10:38 AM   #12
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I'm pretty sure SAAMI lists desired test barrel lengths by caliber... but for rifles, the most common is see is 24".
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Old January 26, 2017, 11:13 AM   #13
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Sounds like the ammo manufacturers have borrowed from the auto makers advertising department.
Horsepower sells cars, energy sells ammo.
Neither one tells the whole story, though.
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Old January 26, 2017, 11:20 AM   #14
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Not a gimmick, not the whole story either.

The OP is more gimmicky than what it complains about if facts still matter.

They can't put it all on the box. Those that do are attempting to provide a bit of information to their customers. Is it marketing? It is useful? Yes to both.

The gun industry, and the consumers thereof, really need to do less shaming, less complaining, and more getting new shooters to the range, teaching the skills of hunting, marksmanship, etc.
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Old January 26, 2017, 12:57 PM   #15
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Clearly, you didn't grow up shooting when I did.
back in the "stone age" ammo makers didn't put any velocity, trajectory, or energy information on the box. Caliber and bullet weight and usually bullet type was it. (along with the boilerplate "use only in..." type info).
Im just barely old enough to remember. Back in the day all you had to choose from was what the stores had on the self. There were a lot less options, and a lot less ammo gimmiks.... ammo mfgs simply just made a few of the most popular loads to sammi spec and called it good. So you didnt nitpick the load you nit picked the caliber/gun and when someone didnt get the result they expected they traded the whole gun usually for something bigger. If a 9mm didnt work for you, youd go buy a 45 and call it good, something like that.. But pretty much you already knew what to expect with what you got simply by the calibers reputation (I dont think anyones ever questioned the "stopping power" of a 45acp)

Nowadays, there are so many gimmik load options it wouldnt surprise me to find some 9mm HP with only 200ft lbs... If you dont get the results you expected, you have to question the load you bought before you consider trading the gun. These days, If it doesnt list the velocity and energy on the box its a scam.

I think adding ballistic gel data on the box is a good idea actually.
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Old January 26, 2017, 01:09 PM   #16
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Kinetic energy is proportionate to the square of velocity, while it is only directly proportionate to mass.

So, small changes in velocity make a big difference in the amount of energy. Much bigger than changing the weight.

So, it's possible to end up with outrageous amounts of energy by firing a a lightweight (for caliber) projectile at a relatively high velocity. Large amounts of energy make for impressive advertisements.

The problem is that such bullets tend to disintegrate and offer very poor penetration. Energy isn't the whole story.
You are spot on sir, and this is why KE is only a portion of what we should look at when selecting ammunition for certain purposes. But this really isn't a debate on the merits of KE... it's not a perfect measurement of cartridge effectiveness. 45-70 and .223 have ballpark similar KE, but I would much rather take a 45-70 for close-mid range elk hunting than a .223. With that being said, KE will be a ONE pertinent indicator of performance when comparing rounds of the same caliber/approximate weight.

Quote:
They can't put it all on the box. Those that do are attempting to provide a bit of information to their customers. Is it marketing? It is useful? Yes to both.
I agree, which is why I have no qualms about KE being listed on the box. I don't think it's necessarily a marketing "gimmick" per se. Just providing the consumer with relevant information.

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The gun industry, and the consumers thereof, really need to do less shaming, less complaining, and more getting new shooters to the range, teaching the skills of hunting, marksmanship, etc.
Best statement in this whole thread right now.
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Old January 26, 2017, 01:27 PM   #17
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"...the hollow point does much more damage..." Yep. Because it gets bigger in diameter upon impact with the same amount of energy.
A football player at a dead run isn't anywhere near as fast as any bullet.
"...Tissue damage to vital organs, not kinetic energy, is what kills..." Nope. Bullets kill with energy not blood loss or tissue damage. Really the shock that comes from both.
Anyway, the energy they're talking about is the mathematical acquired potential/kinetic energy of a given bullet weight at a given speed. Not a gimmick. It's physics.
And there's no such thing as 'stopping power'. No cartridge, rifle or handgun, will give a 100% guaranteed one shot stop. Physics doesn't allow it.
"...Horsepower sells cars..." To men. Colour sells 'em to women. snicker.
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Old January 26, 2017, 02:47 PM   #18
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Kinetic energy numbers have been included in hunting regulations in in various states in the US, and in Africa, and Europe. And in ammunition specifications provided by military and law enforcement agencies all over the world, and by the companies that make that ammunition. And in specifications from manufacturers and buyers of other military weapons, such as mines. And in specifications written up by manufacturers and buyers of bullet resistant products.
A lot of people must find the concept useful.
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Old January 26, 2017, 06:40 PM   #19
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Regardless of one's personal view about the usefulness of the information, energy numbers are included on a lot of ammunition simply as a point of comparison.

It's like 0-60 mph times for econo cars and light trucks .... not very useful, but a point of comparison between models.


And for some cartridges, the energy number(s) are included because the cartridge meets some magic number that has been adopted as a requirement for a specific application.
.327 Federal Magnum, for example, listed energy figures on the ammunition when it was released, because the American Eagle 100 gr soft point load met the 500 ft-lb energy requirement for hunting big game in certain states; and the other loads included the information to show that they came up shy (and were illegal in those states).
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Old January 26, 2017, 09:24 PM   #20
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I love the energy v. momentum discussion every time it comes up in this forum. If you place equal energy into a lightweight bullet versus a heavy one, the light one will travel faster, arrive quicker, and with greater velocity. Both retain equal energy, minus that lost in transit to friction. Energy quickly transferred is energy quickly lost. Energy becomes heat as the bullet deforms itself as well as the struck object. An object with greater mass (which is conserved), retains the energy and transfers it more slowly.

The human on earth has tremendous mass and a fall from standing produces enough potential to kinetic energy to crack most skulls wide open.

The sun has tremendous energy, and radiation, although absorbed as molecular electric / heat / kinetic energy in the skin and organs, hardly makes us bleed.

The key is in the proper proportion, delivered at the appropriate rate. One cannot with equal energy split wood with a fast machete, or a slow sledge, but only a sharp axe.
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Old January 26, 2017, 11:56 PM   #21
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No cartridge, rifle or handgun, will give a 100% guaranteed one shot stop. Physics doesn't allow it.
While I do believe this to be true, I have my doubts about the 90mm recoilless rifle..(with a COM hit, of course)..

Quote:
.327 Federal Magnum, for example, listed energy figures on the ammunition when it was released, because the American Eagle 100 gr soft point load met the 500 ft-lb energy requirement for hunting big game in certain states; and the other loads included the information to show that they came up shy (and were illegal in those states).
until you mentioned it, I had forgotten how now, many states include an energy requirement in defining what is legal for what game.

In light of that, putting that number on the ammo box makes good sense, providing a handy "in the field" reference that shows your ammo meets the requirement. (or doesn't).
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Old January 27, 2017, 12:35 AM   #22
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I haven't seen any states hunting ammo energy requirement that wasn't flawed. Obviously many wildlife officials are not that familiar with guns. In my state you can legally hunt deer with a .25acp. Thank god even the craziest of yahoos are smarter than that but I'm sure the wildlife official has a degree in something...
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Old January 27, 2017, 10:00 AM   #23
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Obviously many wildlife officials are not that familiar with guns.
Maybe it's because I'm in a very gun-friendly locale, but I constantly hear about LEO's and Game Wardens being en masse ignorant about firearms but my observation proves this to be totally false. Most sworn wildlife officials I know hunt, fish, teach CCW classes, and are avid shooters. At least half of the cops I know are avid shooters, and most of the rest I would describe as "better than just proficient."

If you are talking about the eggheads that actually write the law, I would agree with you. They probably know virtually nothing about firearms and the low K/E requirement is based off of ensuring that bow hunting will be allowed. As we know, K/E of a arrow and K/E of a bullet are apples to oranges.
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Old January 27, 2017, 10:35 AM   #24
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Energy if fun to play with but is not the end-all when it comes to hunting bullets.

I attended the Northwestern Traffic Institute on Traffic Accident Reconstruction.

We played with the numbers where if you got a bumble bee going fast enough it would exceed the energy of a freight train (eng. only) and it theory would stop a freight train.

But we know math alone will not stop a freight train, no matter how fast you can get a bubble bee to fly.

A more realistic example it comparing two bullets of the same weight at the same velocity.

Lets say, a 150 FMJ 30 cal bullet going 2700 fps, with a 150 gr. Soft point 30 cal bullet going 2700 fps. Both are going to have the same KE, about 2430 ft lbs. (2428.7 to be exact).

Which of the two would make the better hunting bullet. One more then likely will pass through, expending its energy in the air until it hits the ground someplace down range. The other is more then likely going to expand and expend its energy in the critter.

But like I said, its fun to play with the numbers. Not as much fun now as it use to be when we had to use a slide rule, but still fun.

As I have said in the past, "sniping isn't about the gun/ammo, its about the weaponization of math".
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Old January 27, 2017, 03:14 PM   #25
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If you could get that bumble bee going fast enough, it would turn to plasma, which could burn a hole through that train engine, lengthwise...or so the math says..

Our thinking about "what" does "what" when it comes to bullet performance in a target medium is somewhat channeled by the terms and math we use to describe it.

Kinetic energy is energy of motion, energy doing work, and a bullet has that as long as it is moving, but, that is all just potential until it strikes the target.

Target resistance forces some of that energy to work on the bullet, itself, which is why a hollow point expands. You could say that the energy used to expand the bullet is "lost" because it doesn't directly affect the target, and be mathematically correct. However, like energy lost when the bullet exits, it doesn't matter. All that matters is that there is enough energy to drive the bullet where it needs to go to get the job done, under all possible conditions.

If you have enough to do that, where any excess goes is a moot point.
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