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Help! Bullets And Impact Math

  1. Feb 18, 2008 #1
    Help! Bullets And Impact Math!!

    Hi there. I will introduce myself as an aspiring mind. However though my study skills are well developed, my advanced math skill are sadly lacking . . .:smile:

    Here is the thing, I have developed a passion for the study ballistics. And after sometime I have developed a theory, a theory that requires math, and so I have come here . . .

    If you visit a gun forum, you will find all kinds of macho bravado that we like to call the "caliber war". Basically it is all unsubstantiated myth backed up by very little data. Basically it goes like this "Big gun . . . huge bullet COOL MAN!" :rolleyes: what a load of bunk . . . seriously it is very annoying. In reality it is all about the science NOT the bravado.

    The theory goes like this: What ACTUALLY makes a bullet the most effective is a combination of three independent factors. 1.) bullet diameter (or caliber) 2.) its velocity upon impact. and 3.) It's weight. Now without getting all gross about what happens when a bullet hits something, there are two things that end up happening: 1.) a permanent cavity is formed (called the crush cavity--this is the actual hole itself that it makes) and 2.) a Temporary crush cavity (this is the temporary expansion imparted upon a "fluid-like" medium by a high velocity projectile.) THIS temporary cavity is why I have come to this forum . . .

    Here is what I kneed to know.

    Specifically, what is the overall energy in newtons, psi, (whatever) of this "shock wave" depending on the diameter of the projectile, its velocity and it mass??? I just can't do this on my own, but I think that someone here can :wink: I am calling it the caliber trinity . . . and if my hypothesis can represented mathematically we might just be able to make a small bit of ballistics history.

    Here is the list: Keep in mind that these are EXPANDING BULLETS so the diameter is the final expansion in inches not the actual bullet caliber. If you can tell me the force of each individual shock wave that each of these loads can generate I would literally be ecstatic. IF it can be done I will add a second list. But I think I have come to the right place . . . dazzle me :approve:

    (Note that: 1.) weight of bullet is measured in grains (not sure what the conversion is) 2.) velocity is in FPS 3.) penetration in inches is in a ballistics gelatin medium designed to mimic living tissue and 4.) DIAMETER of bullet upon entering the medium in inches.

    DoubleTap 9mm+P
    115gr. Gold Dot JHP @ 1415fps - 12.00" / .70"
    124gr. Gold Dot JHP @ 1310fps - 13.25" / .70"
    147gr. Gold Dot JHP @ 1125fps - 14.00" / .66"

    DoubleTap .40 S&W
    135gr. Nosler JHP @ 1375fps - 12.10" / .72"
    155gr Gold Dot JHP @ 1275fps - 13.00" / .76"
    165gr Gold Dot JHP @ 1200fps - 14.0" / .70"
    180gr Gold Dot JHP @ 1100fps - 14.75" / .68"
    200gr XTP @ 1050fps - 17.75" / .59"

    DoubleTap .357 Sig
    115gr Gold Dot JHP @ 1550fps - 12.25" / .71"
    125gr Gold Dot JHP @ 1450fps - 14.5" / .66"
    147gr Gold Dot JHP @ 1250fps - 14.75" / .73"

    DoubleTap .357 Magnum
    125gr. Gold Dot JHP @ 1600fps - 12.75" / .69"
    158gr. Gold Dot JHP @ 1400fps - 19.0" .56"

    DoubleTap .45ACP
    185gr Gold Dot JHP @ 1225fps - 12.75" / .82"
    200gr Gold Dot JHP @ 1125fps - 14.25" / .88"
    230gr Gold Dot JHP @ 1010fps - 15.25" / .95"
    Last edited: Feb 18, 2008
  2. jcsd
  3. Feb 18, 2008 #2
    Although I have nothing constructive to add I'll bet my money that someone has already done this study and found more what your looking for.
  4. Feb 19, 2008 #3


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  5. Feb 21, 2008 #4
    Been out of town, I will post again in about two days. Thanks for the links I will try to go over them as much as possible while I'm ruining around.

    Response to Bystander: the link you provided is an excellent link. I have had it down loaded to my computer for sometime and have read it in full. Thanks though . . .

    Response to Baseplayer142: Not this . . . their are many studies of ballistics. But no where have I found any data even remotely close to what I am looking for. If anyone has knowledge of such data feel free to post it. The link provided by bystander is about as close as you will come, but that particular study only involves a single sphere, of a single size, of a single weight . . . one single time. (sorry about my spelling I am typing really fast) There is no comparison for different size spheres, possessing different weights at different velocities (not to mention the actual force involved with the shockwave (temporary cavity) w Which is what I am looking for.
    Last edited: Feb 21, 2008
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