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Thread: Interesting thread on GT about bullet performance in actual shootings

  1. #41
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    "Correct me if I am wrong, but won't the flat meplat bullets penetrate without tumbling, while the round-nose FMJ's tumble, thus decreasing penetration?"
    Not necessarily. For example, while A475 GI M1911 .45 ACP 230 gr FMJ does not tend to yaw or "tumble" in tissue, the AA18 .45 ACP 185 gr +P truncated cone FMJ issued for the Mk23 Mod0 pistol did yaw, often times turning 180 degrees.

  2. #42
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    Quote Originally Posted by DocGKR View Post
    Not necessarily. For example, while A475 GI M1911 .45 ACP 230 gr FMJ does not tend to yaw or "tumble" in tissue, the AA18 .45 ACP 185 gr +P truncated cone FMJ issued for the Mk23 Mod0 pistol did yaw, often times turning 180 degrees.
    Maybe due to the shorter length of the 185gr? I guess it is weight/caliber specific. Kinda blows that theory out of the water (FP=no tumble).

    I also had another sort of question, what is your opinion of the work done by Maj. Ralph W. French, MAC, USA (Ret.), and Brig. Gen. George R. Callender, USA (Ret.) with regards to terminal ballistics? They tend to focus heavily on velocity and energy, but they have supported their claims well, at least as far as a layman like myself can determine. Here is the particular document I am currently perusing.

    http://history.amedd.army.mil/booksd...s/chapter2.htm
    Last edited by WS6; 01-03-10 at 20:11.

  3. #43
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    Quote Originally Posted by Phila PD View Post
    Feed more reliably= Good
    This only matters if your gun doesn't feed modern JHPs properly. And in that case, I'd recommend changing guns, not ammo.

    There are countless combinations of modern handgun and modern JHP that provide the same level of feed reliability as those same guns with FMJ.

    Penetration= Good
    This only matters if your current JHPs are deficient in penetration. Even the FBI -- champion of the deep penetrating handgun bullet -- agrees that beyond a certain point, deeper penetration is not only unnecessary but unwanted.

    There are countless modern JHP designs which provide proven penetration.

    Hollow-point expansion= Does not matter?
    Reduced chance of overpenetration matters. (note: "reduced chance" is not a 100% guarantee that no bullet will ever overpentrate)

    Larger wound track matters. (note: "larger" is not a 100% guarantee that the BG will drop dead instantaneously)

  4. #44
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    ToddG's comments are right on target, so to speak...

    "I also had another sort of question, what is your opinion of the work done by Maj. Ralph W. French, MAC, USA (Ret.), and Brig. Gen. George R. Callender, USA (Ret.) with regards to terminal ballistics?"
    It is interesting from a historical perspective, but not relevant to today's knowledge base; kind of like reading a surgical atlas from the 1930's--interesting, but it is not what I would want my surgeon to be using when operating on me today...

  5. #45
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    Is anyone here familiar with the work of Carroll E. Peters?

    His book, 'Defensive Handgun Effectiveness', published in 1977, fits in well with this discussion.

    Part of his book was based on bullet energy transfer tests done at the Southwestern Institute of Forensic Sciences using 5.9 inches of 20% ballistic gelatin at 10 degrees C .

    In those tests he noted that the W-W .38 Special +P FMJ 150 gr. metal penetrating bullet behaved in a similar manner to a +P lead 158 gr. SWC bullet of the same caliber. It is a truncated conical bullet with a large tangent angle nose shape.

    A bullet using that nose shape should function well in a semiautomatic pistol and could possibly increase the effectiveness of FMJ bullets.

  6. #46
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    Quote Originally Posted by DocGKR View Post
    Not necessarily. For example, while A475 GI M1911 .45 ACP 230 gr FMJ does not tend to yaw or "tumble" in tissue, the AA18 .45 ACP 185 gr +P truncated cone FMJ issued for the Mk23 Mod0 pistol did yaw, often times turning 180 degrees.
    May I ask if this load is still used? I understand it was used by US SF when HP was not allowed.

    What is the muzzle velocity of this load, out of a 5" barrel? Is there any noticeable advantage in terminal effect using this load instead of more conventional, std. vel, round nose FMJ 45 ACP ammo? I think at least the 185+P FMJ-FP would penetrate better some barriers.

  7. #47
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    I don't have documents to support this, but going from memory of several thousand gunshot wounds where seemingly intact FMJ bullets have been retained in the body, the majority of those bullets have ended up in a base-first presentation (180 degrees from initial). In many cases the bullet 'points' to the entrance wound when viewed radiologically.
    I don't think it is surprising, since the centre of gravity of most bullets is towards the base. At some point during its terminal trajectory, one of these rounds will be presenting its entire length as a 'striking surface' in that wound channel.
    Vincent DiMaio pointed this out in his book "Gunshot Wounds."

  8. #48
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    As shown here:

    https://www.m4carbine.net/showthread.php?t=19937



    The 9 mm para has a fairly pointed ogive, and looks more unstable than the blunter 380 and 45 ACP FMJ-RN bullets.

    I wonder if there is a way to promote earlier tumbing.

  9. #49
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    Quote Originally Posted by TiroFijo View Post
    I wonder if there is a way to promote earlier tumbing.
    There are couple of ways. A more triangular(or tear drop) bullet profile would result in a bullet with a heavier rear that will want to flip more rapidly and/or you can use a spoon tip like was tried in the H&K 4.6mm.

    The spoon tip does a couple theoretical things. It causes a lift/sucking effect on the point based on Bernoulli's Principle through fluids(water/air), and would result in faster destabilization. It also helps to slow down the bullet spin as it is penetration tissue, and thus the bullet is allowed to destabilize. The flat edge of the spoon catches on the tissue to slow down spin. As long as the bullet keeps a significant spin going, it will correct any yawing and straighten out the flight path.
    Last edited by Marcus L.; 01-04-10 at 11:14.
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  10. #50
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    Interesting... perhaps a more pointed nose will work. There are many lead 115 gr truncated cone designs (casting molds) that have this "triangular" nose.

    Stability/accuracy is not problem, since the 9 mm twist rate (for tradition?) is much faster than needed: 1-10" vs 1-16" (or slower) in 38/357 that fire bullets up to 180 gr. I've fired many of these TC designs and they grop very well.

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