Homemade ballistic gel

Discussion in '10mm Reloading Forum' started by Andrew Wiggin, Oct 2, 2012.


  1. Go to the end of the thread for the most recent test.


    So my lovely and thoughtful wife bought me a 10mm Witness for Christmas and I've had a lot of fun working up loads for it. Problem is there really isn't a whole lot of terminal ballistic data available so I have no idea which bullets will hold together well or penetrate to what depth. I did a couple water tests but those were less than definitive and disappointing if the penetration results were to be believed. Worse, it seemed that they were inconsistent with other available data. So I decided the only way to get good data was to gather it myself. Here is my attempt at ballistic gel. Let me know how badly you think I did.

    Proper ballistic gelatin is 10% by weight 250 bloom photographer's gelatin. That means 10% of the weight is gelatin and 90% of the weight is water. It is kept at 39° F and is calibrated by a .177 cal steel BB at 590 fps +/- 15fps. The calibration shot(s) should be between 2.95"-3.74". 250 bloom photographer's gelatin is expensive so I bought grocery store unflavored gelatin. I did the math and found that 10% should put me at about 1 cup of water per ounce of gelatin. I bought three 8oz packages of Kroger gelatin and mixed it up with 24 cups of water but it didn't calibrate correctly. I bought another three 8oz packages, Knox this time and mixed it with 18 cups of water, melted both batches down and mixed together. So that's a total of 48oz (by weight) of gelatin with 42 fl oz of water.That got me close to what I was looking for but I had to melt and add water a couple times again. The final mix was 48 oz gelatin to 45 cups water. I've since doubled the batch and confirmed that ratio, but if you make some up, it might be better for you to start a cup or two short just because it's easier to add water than remove it. My procedure follows.

    Open all the packages into a bowl for easy pouring. Measure 45 (or a bit less) cups of hot tap water (I have since found that cold water produces less clumping so I mix it cold and then heat in a double boiler) into a bucket, along with a few drops of bleach (to prevent mold) and a few drops of Jet Dry to prevent foaming. Start the water moving with a mixer and slowly pour in the gelatin. Be careful to pour slowly enough to avoid clumps but some are probably inevitable. Allow to cool and refrigerate for about a day. Heat in a double boiler until just melted, stir, and pour into molds. Allow to cool and refrigerate again for several days. It gets firmer after several days and it has to be all the way down to 39° throughout for calibration to have any meaning. Fire a 590 fps +/- 15 fps .177 cal BB into the block and measure the penetration. In the picture below, the bottom shot took place at about one day in the fridge and it measured 4". The shots above that took place at about three days and measure, bottom to top: 3", 3 1/8", 3 1/4", 3 1/8". The other picture was a .22 cal pellet from a Benjamin Sheridan pellet rifle just for fun. It penetrated 4 1/2".

    After a test, I cut the blocks to get good photos of the "wound" track and put them in a double boiler to remelt. I just use a plastic bucket (about 2 gal, I think) for the gelatin and a large stock pot for the water. I keep the stove on medium and try not to let the gelatin completely melt while it's in the water. As it melts, I pour it out and add more blocks to keep the temperature from getting too high. When I'm down to the last of it, I remove it from the heat before it's completely melted and let it finish melting on the counter. The warm gelatin is usually enough to melt a few smaller chunks. I pour through a wire mesh grease splatter screen first to remove the larger chunks of denim, dirt, lead, copper, and BBs, then I pour through a "permanent" wire mesh coffee filter to remove the smaller particles. It all goes into a large bucket until it's all melted and then into the molds. For molds I just use cheap Sterlite tubs from Walmart.

    [​IMG]

    [​IMG]




    Here's a new test with a bit more precise data:

    BB calibration: 590.8 fps, 3" penetration
    .22lr from Walther P-22: 36 gr CCI Mini-Mag hollow point at 970.0 fps, 8 3/8" penetration
    I got distracted by something shiny and forgot to place 4 layers of denim in front of the .22lr shot.


    [​IMG]
     

    Wanna kill these ads? We can help!
    #1 Andrew Wiggin, Oct 2, 2012
    Last edited: Mar 5, 2014
  2. Loading...

    Similar Threads Forum Date
    Shooting LIVE CO2 Cartridges out of a homemade shotgun The Okie Corral Yesterday at 10:30 AM
    $50.00 Homemade Dillon Case Feeder Reloading May 30, 2015
    Homemade booster pump Reloading May 29, 2015
    Road Rage Leads to Fight Involving Sword and Homemade Flail The Okie Corral May 3, 2015
    Homemade chronograph Reloading Feb 21, 2015

  3. I went ahead and melted the blocks down to mix in a cup of water. I think I might actually need two cups but you can always add more water. It's a lot harder to get the water out. I poured the gel through a screen and took a pic and measurements of the .22lr. The retained weight was 35.7 gr and the diameter was approximately 0.335". I didn't find any fragments. There was absolutely no deformation on the pellet.


    [​IMG]
     

    #2 Andrew Wiggin, Oct 2, 2012
    Last edited: Nov 14, 2012
  4. Wow! Maybe you need to find a hobby or smething... :)

    Nice approach, I am interested to see how it plays out.
     
  5. nickE10mm

    nickE10mm F.S.F.O.S.

    3,953
    5
    Very cool ... :popcorn:
     
  6. Taterhead

    Taterhead Counting Beans

    3,279
    8
    Cool project! I barely have enough time these days to keep up with loading and ballistically unloading my brass.

    I look forward to your results. Thanks for starting a cool thread.
     
  7. I like it. Sure, it's a lot of work, but this sounds a lot easier (and cheaper) than true ballistic gelatin.

    Couple questions:
    - What are you using for molds?
    - Why do you have to let the gelatin set up for a day, and then pour it into the molds, instead of putting it straight in the molds? Is this for consistency?

    The BB pictures are cool; it looks like the BB's actually bounced back a tiny bit.

    I wonder if you could inject food dye in the bullet track for better pictures?

    I'm going to have to try some of this. Thanks for posting.
     
  8. It's definitely cheaper but my process is pretty close to what I've read on preparing the real stuff.

    Just using el cheapo Sterlite tubs I found at Home Depot. They are 6 qt, 13 5/8" x 8 1/4" x 4 7/8". (Now I'm using twice as much in larger tubs) Two of them fit my batch of gelatin (48oz dry) perfectly. I wiped the inside of the tubs with some vegetable oil and a paper towel so the gelatin would release easily (I discovered this isn't necessary, either).

    When you first mix the gelatin, it's not really thoroughly mixed and there are small clumps and inconsistencies because the gelatin isn't fully hydrated. It takes some time for the water to completely soak in. It might work to go straight into the double boiler but the procedures I've read for real 10% ordnance gel have it sit for several hours in the fridge.

    I do think the BBs either bounced back, as you say, or split the gelatin farther forward than they actually traveled. Nevertheless, I'm measuring from the leading edge of the BB.

    The track would probably be more visible but then the dye would stay in when I remelted and the gel would gradually darken.


    Recalibrated today and I'm dead on 3" again with a BB velocity of 595.9 fps. I'm going to remelt and add two cups of water. I'm going to shoot this SOB on Saturday, regardless of how it calibrates. I have more opportunities to fiddle with the mix than I do to get out and shoot. I think I'll hit it with a 165 gr Gold Dot at 1,302 fps first.
     
    #7 Andrew Wiggin, Oct 4, 2012
    Last edited: Nov 14, 2012
  9. nickE10mm

    nickE10mm F.S.F.O.S.

    3,953
    5
    :) me likey
     
  10. Very cool, and thanks for the answers. Putting this on my list of projects to do...

    I'd like to see your results when you shoot it.
     
  11. Taterhead

    Taterhead Counting Beans

    3,279
    8
    That should be a winner. Hopefully you'll get some good photos.
     
  12. Definitely. I'll shoot it tomorrow and probably post results on Monday(ish).

    If the test is successful and I'm happy with the performance of the gelatin, I'll post a more straightforward rundown on my process.
     
  13. I had some trouble with my chrono and it missed the velocity on several BB calibration shots. There were also a few that came in well under the acceptable velocity of 590-610fps. My BB gun seems to shoot faster when it's cold. Maybe I'll keep it in the cooler with the gel next time. [​IMG] I finally got a couple shots that were close to the right velocity so the calibration shot will be 586.4 fps (still a touch low) and 3.5". The 10mm shots are taken through 4 layers of denim using an EAA Witness 4.5" barrel.

    First up is 180 gr XTP over 11.8gr of AA#7, 1.255" COL, at a measured impact velocity of 1,290. Penetration is 13.25". It exited the first block and went a about an inch and a quarter into the second block. Next time I'll have to cut the blocks even so there is no air space between them. I don't know how much, if any, effect that has. You can see that this bullet fragmented a bit. I was going to weigh the recovered fragments, but the piece you see in the on picture got left out there. Sorry. Maximum expansion is 0.898" and minimum is 0.636". Retained weight is 174.8 gr.

    [ame="http://www.youtube.com/watch?v=XahzIeDo1Vk"]10mm 180gr XTP @ 1,290 fps gelatin test - YouTube[/ame]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
    #12 Andrew Wiggin, Oct 8, 2012
    Last edited: Nov 14, 2012
  14. Deleted to speed page loading.
     
    #13 Andrew Wiggin, Oct 8, 2012
    Last edited: Nov 14, 2012
  15. nickE10mm

    nickE10mm F.S.F.O.S.

    3,953
    5
    I asked too soon ... removed post.
     
    #14 nickE10mm, Oct 8, 2012
    Last edited: Oct 8, 2012
  16. Since the XTP barely touched the second block, I reversed it and placed it at the front. Next up is 165 gr Gold Dot over 12.3 gr of AA#7, 1.255". I missed the actual impact velocity of this shot but the average for this load is 1,310 fps. Penetration was 12". This shot exited the first block and was found laying between the two. There was absolutely no fragmentation or jacket separation. These Gold Dots are TOUGH. Maximum expansion was 0.837" and minimum was 0.779". Retained weight was 165.0gr.


    [ame="http://www.youtube.com/watch?v=FR14jBsZpWk"]10mm 165 gr Gold Dot @ 1,310 fps gelatin test - YouTube[/ame]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
    #15 Andrew Wiggin, Oct 8, 2012
    Last edited: Nov 14, 2012
  17. Deleted to speed page loading.
     
    #16 Andrew Wiggin, Oct 8, 2012
    Last edited: Nov 14, 2012
  18. Taterhead

    Taterhead Counting Beans

    3,279
    8
    Nice work, Andrew. I really like those 165 gr Gold Dots. That seems to be a really good speed for them.

    Quick side note, you probably mean 1.255" COL rather than 2.255" in posts 12 & 15.
     
  19. LOL, sorry. I'll fix it.
     
  20. Cool stuff, thanks for posting your results.

    Re. the space between the blocks, how about flipping one block upside down? That should let the ends mate up if they're both from the same mold.
     
  21. I feel kinda dumb now. Good call.
     

Share This Page

Duty Gear at CopsPlus