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Thread: Predictive tests in water

  1. #101
    Quote Originally Posted by Lost River View Post
    Open admissions of human error and corrections lend a sense of credibility in my book. Quite frankly, it is normal. It is part of the regular work process.
    To make no mistakes is not in the power of man; but from their errors and mistakes the wise and good learn wisdom for the future.” ―Plutarch
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

  2. #102
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    Response from Ronald L Jones (IWBA full-member)

    Quote Originally Posted by the Schwartz View Post
    I was struck that folks like Ronald Jones (Jones RL. Water Testing .38 Special +P Hollow Points. Wound Ballistics Rev 1997;3(1): 13 - 16) were relegated to relying upon charts instead of using the equations themselves; closed forms make that possible and being able to avail oneself of that ability means that one gains a certain autonomy, not to mention accuracy, by being able to compute results rather than having to depend on someone else to do it for them.
    Sir, I read Duncan MacPherson's book all by myself, twice. Then I was able to figure out for myself how to use the information in that book to estimate ammo performance for my own personal needs. You see, I figured I should know what to expect from my own firearm/ammunition combination in case I should ever need to use it for self-defense. After doing the first tests with .38+P hollow points, I sent my data to Duncan MacPherson to see what he thought of it, and he encouraged me to submit it for publication in the IWBA's journal, the Wound Ballistics Review. My article was accepted for publication, including acceptance by the editor, Dr. Martin L. Fackler. I was published 3 times total; the other 2 times were for .380 ACP hollow points and .357 Magnum hollow points.

    Prior to this, a question was posed by Dr. Fackler on problems with ballistic gelatin (WBR, Vol 2, No. 3, Pg. 3, Paragraph 2) that I was able to solve, and my answer was published in the following journal (WBR, Vol 2, No. 4, Page 5, last paragraph).

    Also, I was asked to speak at the last IWBA Conference on my water-testing procedure and method, I gave papers that were requested for that, and they were accepted.

    In closing, this all started because I was interested in wound ballistics for my own personal use, it expanded when Duncan MacPherson encouraged me to go beyond that, I was published 3 times, and eventually asked to speak at the IWBA Conference. And do you want to know the most interesting thing about all of this, sir? I am a high school graduate who never went to college. Imagine that!

    -Ronald L Jones (IWBA full-member)

  3. #103
    In the interest of providing a clear understanding of what I stated in the post that you quoted only partially in your post (#102, 26th February 2022), I have restored the complete context surrounding the remarks that I made in post #51 (21st August 2018).


    Quote Originally Posted by Glock17JHP View Post

    Quote Originally Posted by the Schwartz View Post
    One of the reasons that I wrote Quantitative Ammunition Selection in the manner that I did—that is, avoiding technical terminology, or when its use was unavoidable, defining it in easy-to-understand terms—was to provide access to penetration equations to the ordinary average guy (like me) much as the late Stephen Hawking did with his seminal book, A Brief History of Time. Realizing that not everyone can solve partial derivatives or integrate by substitution in their heads, I elected to present the modified Poncelet and THOR power law, in Quantitative Ammunition Selection as closed form equations with step-by-step examples laid out much like those found in mathematics textbooks. I was struck that folks like Ronald Jones (Jones RL. Water Testing .38 Special +P Hollow Points. Wound Ballistics Rev 1997;3(1): 13 - 16) were relegated to relying upon charts instead of using the equations themselves; closed forms make that possible and being able to avail oneself of that ability means that one gains a certain autonomy, not to mention accuracy, by being able to compute results rather than having to depend on someone else to do it for them.
    Sir, I read Duncan MacPherson's book all by myself, twice. Then I was able to figure out for myself how to use the information in that book to estimate ammo performance for my own personal needs. You see, I figured I should know what to expect from my own firearm/ammunition combination in case I should ever need to use it for self-defense. After doing the first tests with .38+P hollow points, I sent my data to Duncan MacPherson to see what he thought of it, and he encouraged me to submit it for publication in the IWBA's journal, the Wound Ballistics Review. My article was accepted for publication, including acceptance by the editor, Dr. Martin L. Fackler. I was published 3 times total; the other 2 times were for .380 ACP hollow points and .357 Magnum hollow points.

    Prior to this, a question was posed by Dr. Fackler on problems with ballistic gelatin (WBR, Vol 2, No. 3, Pg. 3, Paragraph 2) that I was able to solve, and my answer was published in the following journal (WBR, Vol 2, No. 4, Page 5, last paragraph).

    Also, I was asked to speak at the last IWBA Conference on my water-testing procedure and method, I gave papers that were requested for that, and they were accepted.

    In closing, this all started because I was interested in wound ballistics for my own personal use, it expanded when Duncan MacPherson encouraged me to go beyond that, I was published 3 times, and eventually asked to speak at the IWBA Conference. And do you want to know the most interesting thing about all of this, sir? I am a high school graduate who never went to college. Imagine that!

    -Ronald L Jones (IWBA full-member)
    On page 14 of "Jones RL. Water Testing .38 Special +P Hollow Points" in Wound Ballistics Rev. 1997;3(1): 13-16 under the section heading of ''Analysis and Conclusions'' you stated and I quote; ''The penetration of each of the rounds tested was estimated using Figures 10-6 and 10-7 as described on page 251 of "Bullet Penetration" by Duncan MacPherson. (Note: some of the data points fell beyond the boundaries of figures 10-6 and 10-7, and were calculated separately by Duncan MacPherson for the author.)'' That statement confirms that you were indeed relegated to relying upon the charts (specifically Figures 10-6 and 10-7 on pages 252 and 253, respectively) as opposed to performing the computations yourself.

    I stand by my commentary above cited once again here—

    Quote Originally Posted by the Schwartz View Post
    I was struck that folks like Ronald Jones (Jones RL. Water Testing .38 Special +P Hollow Points. Wound Ballistics Rev 1997;3(1): 13 - 16) were relegated to relying upon charts instead of using the equations themselves; closed forms make that possible and being able to avail oneself of that ability means that one gains a certain autonomy, not to mention accuracy, by being able to compute results rather than having to depend on someone else to do it for them.
    —simply because the information that I cited was factual, truthful, and accurate. As I stated on 21st August 2018, the purpose of writing Quantitative Ammunition Selection was to provide access to ordinary average guys (like us) to mathematical bullet penetration models that do not require ''some assembly before use'' or the use of small, blurry charts and graphs that cannot match the accuracy and assurance of a computed result. It is my aspiration that everyone should have the same sort of access and ability to benefit from these models that experts and professionals have.

    In the event that you have taken exception to my commentary of 21st August 2018, I can assure you that no derision, disparagement, or disrespect was intended towards you (or anyone else for that matter) in the observation that I made in post #51.
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

  4. #104
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    Quote Originally Posted by the Schwartz View Post
    In the event that you have taken exception to my commentary of 21st August 2018, I can assure you that no derision, disparagement, or disrespect was intended towards you (or anyone else for that matter) in the observation that I made in post #51.
    Sir,

    My response was not due to offense, it was sent to give you and everyone else here reading this the 'backstory' on myself. I was attempting to show that if one has a desire to pursue a subject, they should do whatever they can to accomplish that goal. My road took me from reading every gun magazine I could get my hands on, to figuring out how to contact Dr. Fackler who I read about in one of them. I talked with Dr. Fackler, and then he sent me a lot of information while he was at LAIR. When the IWBA started I was able to join as an associate member, and then I tried to figure out how to do my own ammunition testing. My journey eventually led me to using water since that was a lot easier than preparing and using properly calibrated ballistic gelatin.

    The rest of my story is in my previous reply.

    -Ron.

  5. #105
    Quote Originally Posted by Glock17JHP View Post
    Sir,

    My response was not due to offense, it was sent to give you and everyone else here reading this the 'backstory' on myself. I was attempting to show that if one has a desire to pursue a subject, they should do whatever they can to accomplish that goal. My road took me from reading every gun magazine I could get my hands on, to figuring out how to contact Dr. Fackler who I read about in one of them. I talked with Dr. Fackler, and then he sent me a lot of information while he was at LAIR. When the IWBA started I was able to join as an associate member, and then I tried to figure out how to do my own ammunition testing. My journey eventually led me to using water since that was a lot easier than preparing and using properly calibrated ballistic gelatin.

    The rest of my story is in my previous reply.

    -Ron.
    Got it, Ron. Thank you.

    Once we accept the fact that terminal ballistic testing in water has certain limitations that can be resolved through mathematical modeling, it is probably one of the easiest mediums with which to work. The icing on the cake in this case is that if its temperature is kept between 20°C and 50°C, it can be thermally ''tuned'' to duplicate the shock Hugoniot of any imaginable human soft tissue.

    BTW, if you have not gotten around to doing it for yourself, I would be happy to provide you an Excel computational spreadsheet that would free you from having to rely upon the small print and blurry graphs to determine maximum terminal penetration depth. Operation of the comp-sheet is simplicity itself. The comp-sheet is secured against unintentional corruption, just type in a few inputs and it gives you everything you want to a ridiculous degree of precision... maximum terminal penetration depth, wound cavity volume, and wound mass in both regimes (cavitation and non-cavitation).

    Just shoot me a PM.
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

  6. #106
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    Quote Originally Posted by the Schwartz View Post
    BTW, if you have not gotten around to doing it for yourself, I would be happy to provide you an Excel computational spreadsheet that would free you from having to rely upon the small print and blurry graphs to determine maximum terminal penetration depth. Operation of the comp-sheet is simplicity itself. The comp-sheet is secured against unintentional corruption, just type in a few inputs and it gives you everything you want to a ridiculous degree of precision... maximum terminal penetration depth, wound cavity volume, and wound mass in both regimes (cavitation and non-cavitation).

    Just shoot me a PM.
    Sir,

    I'm good... thank you.

    -Ron.

  7. #107
    OK, let's get this thread back on track.

    I thought that it might be interesting to evaluate a subsonic heavy-for-caliber JHP intended for use in short barrels (< 3.5 inches) in water. Test barrier was the ever-popular IWBA 4LD denim barrier.

    Expansion was excellent even though the velocity was somewhat less than I expected from a much longer barrel than intended for this round.

    Predicted penetration is right in the middle of the 12 - 18 inch range specified by the F.B.I. test protocols.

    Federal 9mm 150-grain HST 'Micro' JHP (P9HST5S)

    Date: 20th July 2021
    Temperature: 85°F
    Relative Humidity: 47%

    Test Firearm: unmodified Glock 17, 9x19mm
    Barrel Length: 4.49 inches

    Barrier: 16-ounce cotton denim, four layers
    Range: 21 feet
    Test Medium: H2O @ 71°F

    Average Expanded Diameter: 0.5327 ± 0.0005 inch
    Recovered Weight: 148.9 grains
    Impact Velocity: 954.4 fps

    Name:  FEDERAL 9mm 150 HST JHP.1.jpg
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    Name:  FEDERAL 9mm 150 HST.2.jpg
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    Predictive Analysis:

    Q-model
    DoP: 16.127 inches
    Wound Volume: 2.945 cubic inches
    Wound Mass: 1.770 ounces

    mTHOR model
    DoP: 15.300 inches
    Wound Volume: 2.794 cubic inches
    Wound Mass: 1.679 ounces

    DoP = maximum equivalent depth of penetration in 10% ordnance gelatin (or soft tissue)
    Wound Volume = total volume of the entire wound channel
    Wound Mass = total weight of tissue damaged/destroyed within the entire wound channel
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

  8. #108
    Yesterday, I had occasion to test the ''short barrel'' version of the Speer .45ACP 230-grain JHP from a Ruger American Compact pistol. The instrumental velocity of this particular load, 926.3 feet per second, was particularly impressive given the abbreviated length of the little Ruger's barrel. Performance was exceptional.

    Speer .45 ACP 230-grain Gold Dot JHP (23975GD)
    Date: 3rd July 2023
    Temperature: 90°F
    Relative Humidity: 71%

    Test Firearm: unmodified Ruger American Compact pistol, .45ACP
    Barrel Length: 3.75 inches
    Barrier: 4 layers of 16-ounce cotton denim; IWBA standard
    Range: 10 feet
    Test Medium: H2O @ 77°F

    Front expansion face of test projectile:
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    Rear aspect of test projectile:
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    Average Expanded Diameter: 0.7270 ± 0.0005 inch
    Recovered Weight: 228.6 grains
    Impact Velocity: 926.3 fps

    Predictive Analysis:

    Q-model
    DoP: 12.093 inches
    Wound Mass: 2.479 ounces
    Wound Cavity Volume: 4.112 cubic inches

    m-THOR model
    DoP: 12.337 inches
    Wound Mass: 2.522 ounces
    Wound Cavity Volume: 4.195 cubic inches


    DoP = maximum equivalent depth of penetration in 10% ordnance gelatin (or soft tissue)
    Wound Cavity Volume = total volume contained within the permanent wound channel
    Wound Mass = total weight of tissue damaged/destroyed within the permanent wound channel
    Last edited by the Schwartz; 07-04-2023 at 10:05 PM.
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

  9. #109
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    Quote Originally Posted by the Schwartz View Post
    Yesterday, I had occasion to test the ''short barrel'' version of the Speer .45ACP 230-grain JHP from a Ruger American Compact pistol. The instrumental velocity of this particular load, 926.3 feet per second, was particularly impressive given the abbreviated length of the little Ruger's barrel. Performance was exceptional.

    Speer .45 ACP 230-grain Gold Dot JHP (23975GD)
    Date: 3rd July 2023
    Temperature: 90°F
    Relative Humidity: 71%

    Test Firearm: unmodified Ruger American Compact pistol, .45ACP
    Barrel Length: 3.75 inches
    Barrier: 4 layers of 16-ounce cotton denim; IWBA standard
    Range: 10 feet
    Test Medium: H2O @ 77°F

    Front expansion face of test projectile:
    Name:  IMG_1554.jpg
Views: 254
Size:  47.2 KB

    Rear aspect of test projectile:
    Name:  IMG_1555.jpg
Views: 251
Size:  40.9 KB

    Average Expanded Diameter: 0.7270 ± 0.0005 inch
    Recovered Weight: 228.6 grains
    Impact Velocity: 926.3 fps

    Predictive Analysis:

    Q-model
    DoP: 12.093 inches
    Wound Mass: 2.479 ounces
    Wound Cavity Volume: 4.112 cubic inches

    m-THOR model
    DoP: 12.337 inches
    Wound Mass: 2.522 ounces
    Wound Cavity Volume: 4.195 cubic inches


    DoP = maximum equivalent depth of penetration in 10% ordnance gelatin (or soft tissue)
    Wound Cavity Volume = total volume contained within the permanent wound channel
    Wound Mass = total weight of tissue damaged/destroyed within the permanent wound channel

    That Speer Short Barrel load is listed at 820 fps from a 4-inch barrel on Speer's website. Your data is showing it more than 100 fps higher velocity from a barrel that is 1/4 of an inch shorter, and that has me puzzled.

  10. #110
    Quote Originally Posted by Glock17JHP View Post
    That Speer Short Barrel load is listed at 820 fps from a 4-inch barrel on Speer's website. Your data is showing it more than 100 fps higher velocity from a barrel that is 1/4 of an inch shorter, and that has me puzzled.
    The chronograph used to obtain the test data (impact velocity) has been validated against a Lab Radar Doppler unit on numerous occasions and once—just recently—against a Garmin Xero C1: it has always demonstrated ±0.75% agreement with the other units. I have no reason to distrust the reading that the chronograph provided in this particular test.
    ''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein

    Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.

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