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Thread: Clear Ballistics Gel and Perma-Gel

  1. #11
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    Correct me if I'm wrong, and there's a pretty good chance of that. It seems to me that for the layman, we are really only concerned about the depth of penetration and the size of the expanded projectile, if expansion occurs. We already know, in a general way, how various projectiles interact with tissue based on earlier professional gelatin tests. If a series of tests done with one of the newfangled gels shows performance relatively consistent with 10% ordnance gelatin, wouldn't that indicate that future tests should be similar? What I mean is that it seems like those gels are *close* even if they aren't exactly the same and *close* is probably good enough for most of us, right?

  2. #12
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    Quote Originally Posted by AndrewWiggin View Post
    Correct me if I'm wrong, and there's a pretty good chance of that. It seems to me that for the layman, we are really only concerned about the depth of penetration and the size of the expanded projectile, if expansion occurs. We already know, in a general way, how various projectiles interact with tissue based on earlier professional gelatin tests. If a series of tests done with one of the newfangled gels shows performance relatively consistent with 10% ordnance gelatin, wouldn't that indicate that future tests should be similar? What I mean is that it seems like those gels are *close* even if they aren't exactly the same and *close* is probably good enough for most of us, right?
    That all depends upon what degree and quantity of cross-correlational research one is willing to accept as being "adequate". My preferences are more in line with the major researchers like Doc Roberts and Fackler (so far only water and calibrated ordnance gelatin are correlated) in the field, while someone else may be just fine with a somewhat lesser degree of correlative agreement.

    This is not to say that I am not in favor of seeing the development of more thermally stable mediums (water is the closest to that at this time), but until there is more research like the PDF I linked to (above) my personal preference is stick with the two known quantities. With that thought, I'd sure enjoy seeing more work done in that area.

    If you are interested in the topic, both MacPherson and Schwartz have books out that deal with water and gelatin test mediums here-

    http://www.amazon.com/Bullet-Penetra.../dp/0964357712

    and here-

    www.quantitativeammunitionselection.com



  3. #13
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    This isn't going to be popular, but here goes:

    Water's correlation to 10% ordnance gelatin is somewhat tenuous. I understand that Doc Roberts advised Old Painless that water typically demonstrates approximately 1.8-2x the penetration observed in gelatin (IIRC) but this apparently only applies to service caliber pistol ammunition. The relationship is dramatically different with rifle caliber ammunition and I suspect it may vary substantially with higher velocity pistol ammunition. For example, I've shot 75 gr Prvi Partisan BTHP into water and witnessed less than 18" of penetration, which would be less than 10" in gelatin. Molon's test of the same ammunition shows roughly 14" of penetration in gelatin and my own, less scientific, gelatin test shows the same results.

    I'm not trying to disagree so much about Cleargel, etc. I simply am not qualified to make a statement either way.

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    Quote Originally Posted by AndrewWiggin View Post
    This isn't going to be popular, but here goes:

    Water's correlation to 10% ordnance gelatin is somewhat tenuous. I understand that Doc Roberts advised Old Painless that water typically demonstrates approximately 1.8-2x the penetration observed in gelatin (IIRC) but this apparently only applies to service caliber pistol ammunition. The relationship is dramatically different with rifle caliber ammunition and I suspect it may vary substantially with higher velocity pistol ammunition. For example, I've shot 75 gr Prvi Partisan BTHP into water and witnessed less than 18" of penetration, which would be less than 10" in gelatin. Molon's test of the same ammunition shows roughly 14" of penetration in gelatin and my own, less scientific, gelatin test shows the same results.

    I'm not trying to disagree so much about Cleargel, etc. I simply am not qualified to make a statement either way.
    As for the relationship between gelatin and water tests, I'd go with what Doc Roberts said. The experts- Dr Roberts, Dr Fackler, Dr DiMaio, Mr MacPherson, Mr Schwartz, Mr Wolberg, and many others too numerous to recall- have done the research and weighed in with what seems to be a pretty decent concensus. It (water) works.

    Heck, there's even a Fackler box (a test rig used for doing water tests) named for none other than Doc Fackler himself.

    I've paid (dearly ) for three gelatin tests of my SD ammo in the past and look forward to the day when we'll see an inexpensive, available, thermally stable test medium that has been found to be every bit the equal of calibrated ordnance gelatin.

    I can dream.

  5. #15
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    Quote Originally Posted by 481 View Post
    I've paid (dearly ) for three gelatin tests of my SD ammo in the past and look forward to the day when we'll see an inexpensive, available, thermally stable test medium that has been found to be every bit the equal of calibrated ordnance gelatin.
    Since I hear that ballistic gel is such a pain to use, isn't it time to change the standard to a user friendly material that is close to the old gel?

  6. #16
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    Quote Originally Posted by 481 View Post
    As for the relationship between gelatin and water tests, I'd go with what Doc Roberts said. The experts- Dr Roberts, Dr Fackler, Dr DiMaio, Mr MacPherson, Mr Schwartz, Mr Wolberg, and many others too numerous to recall- have done the research and weighed in with what seems to be a pretty decent concensus. It (water) works.

    Heck, there's even a Fackler box (a test rig used for doing water tests) named for none other than Doc Fackler himself.

    I've paid (dearly ) for three gelatin tests of my SD ammo in the past and look forward to the day when we'll see an inexpensive, available, thermally stable test medium that has been found to be every bit the equal of calibrated ordnance gelatin.

    I can dream.

    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.

  7. #17
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    Quote Originally Posted by 200RNL View Post
    Since I hear that ballistic gel is such a pain to use, isn't it time to change the standard to a user friendly material that is close to the old gel?
    I wouldn't mind seeing that happen. Looks like it is on the way according to the PDF I posted (#10) above.

    Guess we'll just have to be patient.
    Last edited by 481; 12-07-12 at 12:06.

  8. #18
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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.
    Long before I start sending ammo to others, I'll go do a hog hunt myself.

    Why should they have all the fun?

  9. #19
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    Quote Originally Posted by 481 View Post
    As for the relationship between gelatin and water tests, I'd go with what Doc Roberts said. The experts- Dr Roberts, Dr Fackler, Dr DiMaio, Mr MacPherson, Mr Schwartz, Mr Wolberg, and many others too numerous to recall- have done the research and weighed in with what seems to be a pretty decent concensus. It (water) works.

    Heck, there's even a Fackler box (a test rig used for doing water tests) named for none other than Doc Fackler himself.

    I've paid (dearly ) for three gelatin tests of my SD ammo in the past and look forward to the day when we'll see an inexpensive, available, thermally stable test medium that has been found to be every bit the equal of calibrated ordnance gelatin.

    I can dream.
    Even when you can clearly observe that water does not maintain a linear relationship to gelatin in regards to velocity?

  10. #20
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    Quote Originally Posted by AndrewWiggin View Post
    Even when you can clearly observe that water does not maintain a linear relationship to gelatin in regards to velocity?
    Especially so.

    Consider the yields of MacPherson's and Schwartz's bullet penetration models- www.quantitativeammunitionselection.com -plotted on a Cartesian graph. Both models' yields (which are always nearly identical) plotted on such a graph describe a logarithmic curve with V along the ordinate and D along the abscissa. A linear trendline (it's kind of an "average", if you will) drawn through either of these model's yield curves will diverge significantly from either model's logarithmic curves where the velocity is below about 600 fps or above about 1100 fps with the linear "average" grossly over-estimating terminal penetration depth at both extremes of the curve in the vast majority of the cases.

    The deceleration of a bullet in water or gelatin is not a linear function.
    Last edited by 481; 01-29-13 at 21:10.

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