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Thread: Clear Ballistics Gel and Perma-Gel

  1. #21
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    Okay. I hear a lot of folks throwing around the 1.8-2x figure as if that applies equally.

  2. #22
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    Quote Originally Posted by AndrewWiggin View Post
    Okay. I hear a lot of folks throwing around the 1.8-2x figure as if that applies equally.
    That number is just a general estimate and I suspect that Doc Roberts' value is the best of both worlds. I've seen that figure run from 1.5x to 3x depending upon whom one is listening to.

    If you want to "convert" terminal ballistic performance in water to terminal ballistic performance in gelatin there are only two equations that I know of that'll do the job- the Schwartz and MacPherson bullet penetration models.

    I prefer to use them both (and average the results) and they agree with one another unbelievably well given that they are two entirely different sets of equations.
    Last edited by 481; 12-07-12 at 13:29.

  3. #23
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    Quote Originally Posted by WS6 View Post
    Why mess with gel? I simply mail ammo to people who hunt hogs and have them snap pictures of the recovered slugs (if any) and the autopsy as they butcher the animal along with their impressions. You get an idea of what works and what doesn't, albeit you don't have cubic cm of "just like tissue" crushed to bandy about on the internet.

    Gel is useful for comparing one round to another, and is a good simulator, but performance in gel details performance in the real-world is the argument...so performance in the real world will parallel performance in gel, is the other side of that argument. Pigs are cheaper than gel. So if I want to know how a round does in gel, shoot a pig. It works both ways, so to speak, although performance on the pig matters more than the gel, imo.
    The problem is that people will kill a hog or a couple hogs and draw conclusions based on a very small sample size. It can certainly give you useful information but since no two hogs are exactly the same and no two shots are exactly the same it can lead to people drawing incorrect conclusions when good ammo seems to perform poorly or when bad ammo seems to perform well.

    With a large sample size you can draw conclusions with a less consistent medium. If you shot hundreds of hogs with a specific load in nearly the same manner you could draw stronger conclusions, but that is not an easy thing to accomplish. Gel gives a consistent medium to compare different ammo directly with a much smaller sample size because it minimizes variables. Isolating variables is at the very foundation of scientific testing.

    As for switching to a different medium for testing, I'm all for it if we can accomplish that without compromising reliability. One of the reasons the current ballistic gelatin is preferred is because it has already shown to correlate with real world shootings. Changing away from something we know works isn't something to be done without careful consideration.
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  4. #24
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    Quote Originally Posted by AndrewWiggin View Post
    I'm not sure. I've heard the same thing but no one has offered an objective, empirical reason. I'd like to see a series of tests with well documented rifle, pistol, and shotgun rounds to determine whether it produces results consistent with calibrated 250A bloom gelatin or not. If it doesn't, well, there's your answer. If it does, then it may simply be some institutional inertia at work.

    I think there's a big disconnect between what is suitable for a lab doing government contract work and what is suitable for the private citizen looking to determine in a very general way what the performance capabilities of a particular cartridge are.
    Wrong. Doctor Roberts has directly stated that Perma Gel doesn't work, and there are no other tissue simulants currently in use that compare to 10% ordnance gelatin. In the case of Perma-Gel - it was tested by Doctor Roberts and found to be unsuitable as a tissue simulant, although it was useful as a backer material when testing ballistic vests.

    The best suggestion I have for you is to read Duncan McPherson's book on the subject that explains what is required of a good tissue simulant. It takes longer than I care to type out. Suffice it to say: There is certainly a desire to use tissue simulants other than ballistic gel due to gel's sensitivity in how it's prepared and the fact that you can only store blocks for two days. The Army is currently conducting research into physically associative gels (PAGs). I don't yet know how likely they are to replace properly calibrated BG.

  5. #25
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    Quote Originally Posted by 481 View Post
    Long before I start sending ammo to others, I'll go do a hog hunt myself.

    Why should they have all the fun?
    Id love to,but cant right now.

  6. #26
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    Wrong? What is wrong? That private citizens may or may not demand the same level of accuracy? That's an expression of an opinion and simply can't be right or wrong.

    I think what you're getting at is that the gelatin substitutes aren't suitable for lab use. I'm sure you are correct. You know a whole hell of a lot more on this subject than I do but you can't possibly be trying to say that they aren't useful at all, to anyone, because multiple tests performed by independent people have shown reasonably accurate results, compared to published data on well known cartridges. If a wide range of pistol, shotgun, and rifle tests show penetration and projectile upset results roughly consistent with published results from ordnance gelatin, that is sufficient for me. Am I going to base my decision on carry ammo on it? Not likely, but it is interesting.

    It is interesting to see data on cartridges and loads that haven't seen a lot of testing. I respect you but until someone can give me a quantitative reason that I should ignore the similarity between these mediums and calibrated 10% ordnance gelatin, I am going to maintain the position that they are reasonably analogous. Not precisely the same but close enough that I can say "Wow, nice expansion and adequate penetration," or "Holy fragmenting piece of crap, Batman, that thing didn't even make six inches!"

    I'll still keep 180 gr Gold Dots in my G23 and I'll still keep 75 gr Prvi Partisan in my home defense rifle.

  7. #27
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    Many of the polymer gel simulants we have seen are OK for rough handgun penetration data, but generally fail to adequately capture and represent the TSC associated with rifle caliber projectiles. As a result, at this time they are not the best choice for a tissue simulant.

    Water is a less than ideal media, but is simple and cheap--giving a rough assessment of maximum expansion characteristics of JHP handgun projectiles.

    To date, adequately prepared, correctly stored, and properly calibrated ordnance gel remains the best simulant for assessing penetrating projectile characteristics. When interpreted correctly, it does have a very good track record at accurately reflecting results of actual shooting incidents involving human tissue--it is not just useful for comparing projectiles to one another.

  8. #28
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    Quote Originally Posted by DocGKR View Post
    Many of the polymer gel simulants we have seen are OK for rough handgun penetration data, but generally fail to adequately capture and represent the TSC associated with rifle caliber projectiles.
    Doc, could you give us some rough numbers on gel simulants for handgun calibers? What are typical discrepancies compared to ballistic gelatin (in %) when you measure expansion and penetration?

  9. #29
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    Thanks for the reply, Doc. I have noticed that the tests people post with Cleargel show almost no TSC. Do you think the penetration figures for rifle cartridges would be fairly close (within an inch or two) of the results from ordnance gelatin?

  10. #30
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    Quote Originally Posted by AndrewWiggin View Post
    Thanks for the reply, Doc. I have noticed that the tests people post with Cleargel show almost no TSC. Do you think the penetration figures for rifle cartridges would be fairly close (within an inch or two) of the results from ordnance gelatin?
    Necropost!

    I'd like to know this, too. But even more so, I'd like to know the difference between clear gel and "Ordinance gelatin" when it comes to pistol calibers.

    Do pistol bullets tend to penetrate more, or less, or does it "depend"?

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