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Old December 22, 2012, 12:08 PM   #1
Andrew Wiggin
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Join Date: December 22, 2012
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Homemade ballistic gelatin testing

Proper ballistic gelatin is made from 250 bloom photographer's gelatin. Problem is, that stuff is fairly expensive. According to Vyse, the gelatin they use is 250 +/- 5, whereas food gelatin is typically 250 +/- 10. There are also variations in other metrics, which you can read about here. While these variations may invalidate tests for a ballistics lab, I feel that the results should be close enough as to be useful for the layman to get a general idea of how certain loads perform, especially with cartridges such as the 10mm where there just isn't hardly any good, professional data available. At the very least, the data collected should be far more relevant than water or wet pack and probably more accurate than Simtest or Cleargel. I have verified this by shooting my gelatin with a factory Speer Gold Dot 180 gr .40 S&W and a 75 gr PPU BTHP. In the former case, the result was practically identical to a published FBI test and in the latter case, the results were nearly identical to Molon's (from AR15.com and M4carbine.net) test of the same cartridge. I used grocery store gelatin and had to do some fiddling to get the mix right but was eventually able to get consistent calibration results. Proper calibration is a .177 BB fired at 590 fps +/- 15 fps into a 40 degree block of gelatin. Penetration should fall between 2.95" and 3.75". I initially had some trouble getting the right velocity out of my BB gun but I think I've got it figured out now. Here are some of my tests. Penetration, expansion, retained weight, etc. values are in the descriptions for each video.

I use grocery store unflavored gelatin in a ratio of 45 cups of hot water to 48 oz of gelatin, which yields about 2.5 gallons of the mixture. I've since made another batch for a total of about five gallons. The cost is about $6.50 for an 8 oz box of gelatin.

I start by measuring out 45 cups of hot tap water and adding a few drops of bleach (to prevent mold), jet dry (to prevent foaming), and cinnamon oil (to clarify). I then slowly add the gelatin while running the mixer. It's easier to just open all the packets first into a bowl. I try to avoid chunks but I think some are inevitable. Once it's all mixed, it goes into the fridge for about a day. This is necessary to give time for the gelatin to fully hydrate. Then I heat it in a double boiler (actually just a two gallon bucket in a large pot) on the stove to remelt it, stir it well with a long spoon and pour into molds. Then it goes into the refrigerator at 39 degrees F. It needs to refrigerate for at least 3 days to fully cool on the inside. It will need to be calibrated immediately before shooting but you may also want to test it at home to be sure your mix is right before heading out to the range.

Proper calibration is a .177 cal BB at 590 fps +/- 15 fps and the penetration should be between 2.95" and 3.75". If you make multiple blocks, they must each be calibrated.


I've done several different tests and they are all posted to my YouTube channel. Test data is in the video description. I've done several 10mm tests and I'd like to do more, but I also want to test cartridges and loads that may be used for defense but don't see a lot of official testing. Say 7.62x39mm Wolf HP, for example. Here are a couple, if you'd like to see some others, visit my YouTube channel:


10mm MAC Razorback, 165 gr Montana Gold JHP:

YouTube video






.223 75 gr Privi Partisan BTHP:

YouTube video



The largest recovered fragment (19 gr):

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Old December 23, 2012, 09:14 PM   #2
Andrew Wiggin
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Join Date: December 22, 2012
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http://www.youtube.com/watch?v=guNV3RJcj9U


http://www.youtube.com/watch?v=AbQd6F2jh0Q



I also tested 200 gr HAP over 8.3 gr of 800-X at 1,153 fps but I didn't get any video of it. Here are the numbers and pics, though:

Penetration: 19.4"
Weight retention: 198.1 gr
Max expansion: 0.623"
Min expansion: 0.442"







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Old December 25, 2012, 03:47 AM   #3
No1der
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Fascinating stuff.

In case I missed it in the text, have you determined how great the variation between food grade gelatin and ballistic gelatin is? I noticed some of the figures that you mentioned but I can't say I understand them.

Sorry, but gelatin testing is not something I've had any experience with but I'm really curious to learn more. I'd once had the fleeting thought about this subject but never moved forward with it.

Also, if you don't mind, what do you use for molds? Any issues on removing the final cured gelatin from the molds? Any advice on how to remove it without making a horrible mess of things?

Have you tried higher concentrations for gelatin to water solutions?

Have you had experience with actual ballistic gelatin and if you have, what is the primary difference between the two products?

How much time, in your opinion, can the gelatin last at room temperature before it starts to lose some of it's density/integrity? By room temperature I guess I'm talking about the range of 70-75 Degrees Fahrenheit.

Finally, any suggestions on how to get some decent video of the bullet penetration of the gelatin in slowed down motion?

Sorry about all the questions, just really curious about your results and methods with food grade gelatin for ballistic testing.

Edit: Just thought of another question.
Do you test fire by hand or do you use some sort of rig setup sometimes? I would imagine that slight variations in projectile angle could affect the test results, or am I mistaken?
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Last edited by No1der; December 25, 2012 at 03:54 AM.
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Old January 11, 2013, 11:18 PM   #4
Andrew Wiggin
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Join Date: December 22, 2012
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Hey, thanks a lot for all the questions. I really enjoy thinking about and discussing this stuff. I'm not an expert by any means. I'm just interested in the subject and I've done a little reading.

It's hard to say what the variation is. On one hand, it's the same substance, it's all gelatin. On the other hand, the theoretically less consistent food grade stuff could yield inaccurate results. On a hypothetical third hand, my results with Speer Gold Dot .40 S&W and Prvi Partisan .223 were consistent with professional results.

I just use cheap Sterlite plastic bins bought from Walmart. I originally wiped them with a light coat of vegetable oil but that's not really necessary. You just pull out on the wall of the tub while holding the surface of the gelatin and that pops it off each side, then you turn it over and gently shake it. Not very hard, really. It's pretty solid when it's properly mixed.

I have not tried higher concentrations. The older standard of 20% is more expensive, is not the current industry standard, and there is less documentation available for what to expect.

I don't have any experience with the real stuff.

I wouldn't attach any exact time to how long the block can sit out but if it warms up too much, the results will probably be effected. What's most important, in my opinion, is to calibrate with the BB immediately before conducting the test shots. If you don't just leave the block sitting out it the sun for half an hour while you screw off and if the BB calibration is withing tolerance, the results ought to be reasonably accurate, I think.

I don't have a high speed camera. Without that, you're not going to be able to clearly see the bullet passing through the medium.

I shoot by hand. I don't expect that changes in angle will make substantial differences in test results so long as the bullet stays in the block.

I post this stuff to several different forums and I don't always remember to update but I always post to my YouTube channel so you can always check up there. Here are a couple of the latest ones:


.223 69 gr Prvi Partisan BTHP:





http://www.youtube.com/watch?v=FrxyuNWFrAw



10mm 200 gr Black Talon:





http://www.youtube.com/watch?v=NIZlpc_cFtE
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