Is "Muzzle Energy" significant?

[Nathan]

Everybody likes to talk about energy and that's great, but what you want to talk about is the energy to work conversion.

So here we have a 225gr JHP(I'm assuming good) and a 360 gr hard cast solid...your target is a mean, mad, tough, thick skinned, thick skilled Grizzly that now wants to kill you.

Let's assume he is 25 yards away. At >50 yards, you would be tripping a former friend, jumping back in the truck, going back to the cabin, etc.

With your ~1000lbs of energy, what do you want to do. Ideally, you want to penetrate into the innards, create a massive temporary wound cavity and exit blowing bone and tissue out the hole. Sorry, but 45 Colt won't do that to an animal much larger than a 50 yard Antelope or Whitetail Deer. So you must choose.

On a 225gr JHP, a 45 Colt will expand nicely and stop in the middle of the grizzly on a body shot. It used all its energy breaking through bone and expanding. It pooped out in the internals, possibly damaging the heart, but maybe not. The Grizzly now has full blood pressure and a pain in his side.

With a 360gr solid, it will expand almost none...maybe some nose deform hitting a bone. It should have energy left to exit causing massive bleeding and a dramatic loss in blood pressure....I'd go ahead and shoot twice trying to hit the heart this time.

The point is an exiting bullet should create a loss in blood pressure causing quick organ shutdown.

With either bullet, a hit to the heart or spine would be pretty quickly fatal. That is why the work done is more important than the energy in adequately powerful calipers.

Taylor tried to quantify that using diameter in his formulas because diameter alone will do more work going through the animal.

Why is 5.56 so deadly, but then sometimes not?? Because of work. Its velocity is so high that it rips the jacket off and blows up the lead core when it hits and goes through the first bone. If one of the 20+ shards goes through the heart, it will stop. If it goes through stomach and muscle, it will not...at least not quickly. The 62gr steel core just punches a hole doing minimal work.

 

[mavracer]

There is nothing in physics that suggests that an object permanently deformed by the application of energy must somehow be left permanently imbued with energy.

Other that that whole conservation of energy thing, shees and you say I don't understand this stuff.

Third, how do you expect to be taken seriously when you disparage the results that physics provide while simultaneously claiming that you have mastered the topic?

Because their example doesn't work in real life.

A 4 oz hammer at 2.5X the velocity will not drive a nail to the same depth as a 24 oz hammer will. inertia determines the depth the nail is driven not energy.
Yes kinetic energy is present and in the exchange of inertia will transform into heat energy and noise energy.
Just like with bullets as the bullet is deformed there is kinetic energy transformed into a small amount of heat energy.
But we really aren't concerned with the temperature of the bullet are we, since I'm pretty sure it adds no wounding value.
You're left with what is moved in the path of the bullet (permanent wound channel from inertia) and the pressure of the temporary wound channel from the change from kinetic energy into elastic energy.
And ultimately we keep coming back to the facts that in real life testing of bullets impacting test media that the way I'm explaining the difference between energy and inertia works and works for all calibers and what you're trying to say doesn't work with large changes in mass.

How do you expect anybody to take seriously your explanation when it is obviously lacking in the real world?

 

[JohnKSa]

Other that that whole conservation of energy thing, shees and you say I don't understand this stuff.

If you believe that the conservation of energy implies that the permanent deformation of an object as the result of the application of energy means that the permanently deformed object is now forever imbued with energy then yes, you don't understand this stuff.

I find it very interesting to note that you have a lot of the pieces of the puzzle but apparently can't or won't put them together properly. You do seem to understand that kinetic energy is converted into heat energy and noise energy when an object is deformed, but somehow don't understand how that relates to the conservation of energy as it applies to permanent deformation.

Kinetic energy can and does deform things permanently, and in the process is expended in various ways so that energy is conserved--but that does not mean that the deformed object is left with some sort of stored energy as a result.

How do you expect anybody to take seriously your explanation when it is obviously lacking in the real world?

The explanation isn't "mine" except in the sense that I typed it out. It's founded on basic physics and the sources I provided should be more than adequate to demonstrate that it wasn't "my explanation" in the sense of something I came up with myself.

Because their example doesn't work in real life.

The whole point of physics is that it does work in real life. It's actually somewhat amusing that anyone would claim to be an expert on a scientific topic but, when push comes to shove, still claim that it doesn't work in the real world.

Why would anyone spend any time at all learning about energy and momentum if they believed that the physics behind those concepts doesn't work in the real world? More to the point, don't you see the jarring contradiction in trying to convince people that you have mastered a topic you don't believe actually works?

Again, don't take my word for ANY of this. Do the study yourself using the many authoritative sources readily available on the internet or elsewhere. There is absolutely no reason for you to remain deficient on this subject.

 

[mavracer]

If you believe that the conservation of energy implies that the permanent deformation of an object as the result of the application of energy means that the permanently deformed object is now forever imbued with energy then yes, you don't understand this stuff.

Of course it's not forever it can and will transfer heat energy to the surrounding area if and when it cools.

I find it very interesting to note that you have a lot of the pieces of the puzzle but apparently can't or won't put them together properly.

My puzzle pieces fit together fine and the picture is clear. Inertia of the bullet or hammer or whatever else you want to endow with kinetic energy will determine the depth that the nail or bullet will penatrate not the amount of energy present, Since energy can change form the kinetic energy present in the hammer will change form into more heat or pressure.

The explanation isn't "mine" except in the sense that I typed it out.

Trying to equate the kinetic energy to the depth that the nail will be driven is most certianly your explination of how kinetic energy and inertia are related.
The examples you used do not support this they only show the computations of energy.

Why would anyone spend any time at all learning about energy and momentum if they believed that the physics behind those concepts doesn't work in the real world? More to the point, don't you see the jarring contradiction in trying to convince people that you have mastered a topic you don't believe actually works?

The problem is you don't get how the two laws coexist and that kinetic energy doesn't break the laws of inertia, so you don't understand how changes in mass and velocity are easily defined and explained in what effects they have, and ultimately we keep coming back to the facts that in real life testing of bullets impacting test media that the way I'm explaining the difference between energy and inertia works and works for all calibers and what you're trying to say doesn't work with large changes in mass.

 

[JohnKSa]

Of course it's not forever it can and will transfer heat energy to the surrounding area if and when it cools.

If you understood this all along, then your question asking "what kind of energy is the expanded bullet" was total nonsense and your response that conservation of energy is what proves that an object permanently deformed by the application of energy must somehow be left permanently imbued with energy was also nonsensical.

Trying to equate the kinetic energy to the depth that the nail will be driven is most certianly your explination of how kinetic energy and inertia are related.

If you care to put in a minimal amount of effort, you can verify that it's not "my" explanation and that I didn't come up with it.

http://www.wolaver.org/teaching/Chapter_5.pdf

Scroll down to Example 2 in the link.

The problem is you don't get how the two laws coexist and that kinetic energy doesn't break the laws of inertia...

This is a fiction you have manufactured. Nowhere have I even so much as hinted that momentum and kinetic energy contradict either other or that a proper interpretation of either one violates any laws of physics.

... ultimately we keep coming back to the facts that in real life testing of bullets impacting test media that the way I'm explaining the difference between energy and inertia works...

Ultimately what we keep coming back to is that you have devised a personal theory of terminal ballistics which, while apparently intuitive to you, is based on an obviously deficient understanding of the basic physics of moving objects and which requires you to attempt to make and defend obviously improper claims regarding the effects of kinetic energy.

There is a wealth of information relating to this topic on the internet that is easily available for personal study. Which means that you don't have to accept my word blindly. You can easily verify the truth of my claims for yourself.

When presented with hard evidence that your understanding of science is deficient, you respond that the science only works in theory anyway. Which is, in essence, an admission that you have NOT based your personal theory on established science because you don't really believe established science actually works.

 

[mavracer]

Scroll down to Example 2 in the link.

Sorry I couldn't get through the first paragraph lol.

"Friction causes things to slow down, and the
energy is apparently lost. But it’s actually still there in thermal energy"

"But what if friction causes energy to
not be conserved."

Nowhere have I even so much as hinted that momentum and kinetic energy contradict either other or that a proper interpretation of either one violates any laws of physics.

This is not an entirely untrue statement, it's really more that you just choose to ignore the laws when they contradict your explination of how energy determines penatration.

When presented with hard evidence that your understanding of science is deficient, you respond that the science only works in theory anyway. Which is, in essence, an admission that you have NOT based your personal theory on established science because you don't really believe established science actually works.

No what I'm trying to point out is that in theory you can ignore thing like friction and make up numbers that make the math work, but that you really need to prove they work and then the reality of the stuff you ignored will show up in real #s.

Stuff like these from your lesson plan. lesson 5 "We have been looking at systems without friction" so for 4 lesson you pretend the world is a vacuum.

"Let’s say the nail is sticking 2 inch out of the wood before the can hits it, and the can drives it a
distance dn = 1 inch as it comes to rest"

Let's make stuff up

Now, 48 lb is probably more force than you could apply by simply pressing the nail with a
hammer.

seriously who here weighs less than 48 lbs.What is he teaching toddlers.

If it takes Fn = 48 lb of force to move the nail

Just one more assumption

Which goes to show that

"how far dn will the hammer with kinetic energy
EK = 5 ft-lb drive the nail? The work Wn it does on the nail equals EK:
Wn = Fn·dn = (48 lb)·dn = 5 ft-lb
so dn = 5/48 ft = 11/4 inches."

Only really works outside of the real world in imaginary land where energy determins inertia and we can taste color. BTW dispite what the textbooks say Pluto is not in our solar system.

 

[Popo the Kalashnman]

If it's specifically for bear, the heavier bullet will likely penetrate more, and for bear probably the better option. Think 7.62x39 vs 5.56 ... similar muzzle energy, completely different penetration and wounding characteristics.... slow heavy= deep penetration ... light fast= fragmentation

 

[45_auto]

Inertia of the bullet or hammer or whatever else you want to endow with kinetic energy will determine the depth that the nail or bullet will penatrate not the amount of energy present

You really believe that my electric nailgun has a great big hammer inside it?

 

[mavracer]

You really believe that my electric nailgun has a great big hammer inside it?

It has a heavy piston and drive rod usually powered by a electromagnet, although some use a coil spring that's compressed by an electric motor, what did you think was in there energy gremlins?

 

[B.L.E.]

If you accelerate a nail to a fast enough velocity, it will act as its own hammer and go through the board with its own inertia.

 

[JohnKSa]

Sorry I couldn't get through the first paragraph lol.

I'm sorry you couldn't too but at this point it doesn't surprise me. If I hadn't actually been trying to help you gain a better understanding of the topic, I would have found your attempt to rebut the science/math in the source to be comedic. As it is, it's just sad.

This exchange is very nearly the definition of pointless.

You are bent on trying to prove how much you know about physics but your comments make it plain that you don't actually believe that it works in the real world--at least not when your "understanding" conflicts with established science. Therefore, no amount of evidence based on the principles of science/physics will change your mind, or even suggest to you that additional education on the topic would improve your understanding.

 

[Mike Irwin]

Not to mention that the statement that "Pluto is not part of our solar system" is so laughably wrong that it's damned close to a tragic indictment of the educational system in this country.