The Myth of Energy Transfer?

Discussion in 'Vintage Topic Archive (Sept - 2009)' started by Carbin8r, Mar 24, 2008.

  1. Carbin8r

    Carbin8r Member

  2. Ari

    Ari Guest

    Pretty good stuff
     

  3. urotu

    urotu Member

    262
    0
    Interesting read to be sure.
     
  4. Kyu

    Kyu Senior Member Member

    Sorry guys, the physics on this is complete BS.
     
  5. urotu

    urotu Member

    262
    0
    Not to sound rude, but do you have information to back your statement? Most of the research I've seen actually backs up this theory.

    I know that for many years now we've been taught to believe in "knock down" power, but the rate of speed at which a bullet travels is actually detrimental to that effect. That is a bullet travels so fast that it just punches through as opposed to having the time to actually cause enough kinetic energy transfer to "knock" someone down.

    I would be very interested in seeing information to the contrary though, as would others here I'm sure. I've often wondered how much energy is lost or not lost as it were.
     
  6. Ari

    Ari Guest

    After the FBI testing the FBI said

    "Kinetic energy does not wound. Temporary cavity does not wound. The much discussed "shock" of bullet impact is a fable and "knock down" power is a myth. The critical element is penetration. The bullet must pass through the large, blood bearing organs and be of sufficient diameter to promote rapid bleeding. Penetration less than 12 inches is too little, "

    That is quoted straight out of the FBI's conclusions after testing. It is very cut and dry.
     
  7. urotu

    urotu Member

    262
    0
    That was my understanding also, penetration is key. I suppose that a 12 guage slug, or a bean bag round may have some actual "knock down", but otherwise you're SOL.
     
  8. Kyu

    Kyu Senior Member Member

    Sorry, I need to clarify my statement. The result is correct: Energy transfer is mostly bull. However, the reasoning that is used to reach this result is not correct.
     
  9. Ari

    Ari Guest

    Tells us more as we all want to understand what you are thinking. It might help us learn something...
     
  10. The easy way to understand

    I learned in Middle School science the laws of motion. One of those laws says something like: "Every action has an EQUAL and opposite reaction." That means that the force of the handgun against my hand is EQUAL to the force of the bullet leaving the handgun and striking a body. It CANNOT strike with greater force. The bullet is effective because the point of the bullet is a small surface area, and all the force spread out against my hand is concentrated on a dot the size of a bb where the bullet hits. That makes it penetrate, and this penetration is what does the job.
     
  11. It does not matter to effectiveness if the bullet exits. So long as it contacts something vital, it matters not a whit whether a bullet stays inside the body cavity or not. A bullet which doesn't exit and "dumps its energy" into the body, cannot kill any more effectively than one which traverses the victim and exits.

    The most effective bullet will be the one that expands and penetrates all the way through, taking large pieces of things like the spinal colum with it on the way out.
     
  12. griff30

    griff30 Member

    903
    0
    You know it's funny how gun magazines go on and on about "knock down power" and thats what it is guys, media hype. A .45 ACP one of the highly rated rounds for "knock down power" can only knock down a damn bowling pin and not without lots of practice. It will never "pick someone up" or toss them across the room. A 12 gauge will knock a small person over just as firing it will.
     
  13. Kyu

    Kyu Senior Member Member

    Re: The easy way to understand

    Actually, in the case you are describing Newton's 3rd law of motion does not apply. The equal and opposite forces would be the force from the powder explosion against the bullet. Now, if these forces were equal and opposite the bullet would not accelerate, which would be a bad thing. So, we shift to application of Newton's second law of motion. That is: the sum of the forces acting on an object will make it accelerate at a rate proportional to it's mass.

    Now, this imparts linear momentum into the bullet (and also the handgun). So what does linear momentum have to do with anything? Well, EVERYTHING!
    So a force is defined as an objects change in momentum divided by the amount of time it takes for that change in momentum to occur.
    In math terms:
    Momentum = mass x velocity
    force = change in an objects momentum/ the amount of time that takes to occur

    or

    Force = (mass x Final velocity - mass x initial velocity)/ time it takes to happen

    assuming mass is constant

    Force = mass (final velocity - initial velocity)/ time

    So, what does this mean? well, it means that if we can make the time for this to occur very small we can impart a lot of force. why?
    1/0 = infinity

    Don't believe me? Here's 2 things to try:
    1) think about (or try) breaking off a loose thread on a shirt. If you pull quickly, it snaps right off. Slowly, no good.
    2) Any one ever try fighting the recoil of an 8 gauge shotgun? Nuff said.

    Notice I have not once talked about Energy in this entire discussion? Why? I'll add a post on that later!

    cheers,
    Kyu
     
  14. doktor

    doktor Guest

    Though there are others that know much more about the Newtonian laws, my experience has been to deal with the internal "physics" of bodies being hit by different calibers.
    That said, I have seen or heard, first hand of almost every caliber being "lethal." I have also seen people survive, at least temporarily, hit from a great many different calibers, and gauges. I was present when a man walked into the emergency room that had taken a hit left of COM, that took out a very large portion, about 2 inch circle of tissue, where the shot went through, he was dead, but adrenalin carried him inside.
    To put a real life assessment on the question, shotgun blasts be it 12, 16, or 20, does a greater amount of tissue damage, than a .44/.45 caliber, hollow points do slightly more internally than their FMJ counterparts, which does more damage than .38/.357, which does more damage than 9 mm, than ........... I think you get the picture.
    To depend on any caliber to the point that you ignore placement of shot. Of course you can hear stories of tearing an arm off with a .45 ACP, I, personally, have never seen that happen, of course I have only worked in emergency rooms on 3 different continents. I have universally found that hits to the center of mass, regardless of caliber are much more likely to do central damage. The heart, Aorta, Spinal cord, Pulmonary Artery, and both lungs, are all capable of seriously disabling, even dealing lethal force, any caliber that is practiced to the point of placing any round within the area of those vital organs, even if of smaller caliber will do more to make your day improve, than any caliber, even a .454 Casull that hits in a non-vital area, or misses completely. I personally carry .38 +P in a 5 round revolver. Because it is with me, and not my .45 which weighs twice as much, I will be able to hit that area, and do the damage. I don't know many folks that carry a .454 tucked in their waist band, hence, as absolutely more powerful, and as much more damage as it will inflict on the human body when used against it, it won't do near the damage in the gun cabinet, as my .38 Smith will in my hand when hitting the guy/gal that wants my day to go bad.


    Doc
     
  15. Kyu

    Kyu Senior Member Member

    Great points Doc! I think you hit the core of why my scientific rant was trying to say. Any caliber can make some one/thing equally dead.
     
  16. hero_saku39

    hero_saku39 Guest

    I have a problem with this article.......it seems too scattered. What is the "energy transfer myth"? I understand that "knockdown power" is a misnomer and that "stopping power", although overused in marketing, is dependent on many things (that were touched on in this article)

    It doesn't seem to be debunking anything (maybe cause I don't know what this "energy transfer myth" is and it is not defined in the article) but rather simply putting forth data........

    .......and is speed of death the only outcome indicative of "stopping power". The article explains that you can't rely on a psychological effect to stop a bad guy but it also disregards physiological effects that don't necessarily mean loss of conciousness. If you disregard all effects other than death you might as well jump to shot placement as the only factor in stopping a BG.

    The examples used are spot on I guess but not really explained....for example, 4 .357 to a fat guys stomache????? as far as I know the subcutaneous fat pad contains no nerve endings so the wounds that he received were not RELATIVELY painful........so why is the the predominant correlation drawn between the caliber size and physics behind them rather than shot placement (it does talk a bout shot placement but later in the article).

    I guess my problem is what in the hell did I waste my time reading this article for? It is all duh! and doesn't really "debunk" anything unless it is saying that people really believe that caliber is all that matters....??

    did i miss something?
     
  17. Ari

    Ari Guest

    I have seen in many a gun rag and forum folks talking about the energy transfer being the holy grail of stopping a BG quickly. I think this is what he is attacking in his article.
     
  18. hero_saku39

    hero_saku39 Guest

    is the "energy transfer myth" simply the most energy transfered via mass-velocity = the best round for stopping BGs?
     
  19. Carbin8r

    Carbin8r Member

    I take the "energy myth" to be the belief that you want the bullet to expand and lodge inside the body such that all the bullets energy is deposited in the recipient in order for the round to be most effective.

    What they article essentially says is that is crap. Is is all about hitting vital organs. It's not about caliber, velocity, expansion, or any other stat.

    Velocity and expansion only matter insofar as hitting critical areas...expanding bullets give you a slightly greater chance by covering more area and velocity helps ensure the bullets gets enough penetration it reach vitial regions.

    But, based on the material at-hand...if you are a dead-shot (pardon the pun) with a .38 and so-so with a .45, then you are likely to better off with the .38 in the majority of situations.

    Exceptions being if you need penetration (obstacles, body armor, etc). This is where we can get caught up in stats too much. Police and others who tend to find themselves in specific tactical situations really do have different needs than those us of looking for true SD weapons. SD tends to cover very specific (and narrow) range of scenerios.
     
  20. hero_saku39

    hero_saku39 Guest

    ok.....I re read the article (some of it) and my conclusion is this:

    ....the article is correct...........and very poorly written.