How to make ballistic gelatin

Today’s blog is actually a comment sent in by pestbgone. I liked it and several of you did, too, so I made it into a posting.

by pestbgone

B.B. and others,
Thought I’d offer this in case anyone is interested in a fun winter garage project. I apologize for the length.

BALLISTIC GEL recipe and procedure:
I got this info from 
Custom Cartridge, Inc.
I kept the same formulation but modified the procedure to something suitable volume-wise for airguns. It’s not difficult, but it takes a lot of time to do it right.

Materials:
Clear (not frosted) plastic storage box approx 12″ x 6″ x 3″ deep
One 8 oz. box of Knox Unflavored Gelatin (has 32 1/4 oz. pkts)
(Don’t use JELL-O because it has sugar/sweeteners and won’t give consistent results)
10 cups hot water.
Large stainless steel sauce pan.
Wire whisk for stirring.
Gravy separator like this: NORPRO from Kitchen Emporium. 
Fine-toothed hacksaw

Mixing:
This makes 10 cups of gel, which will fill the plastic box about 2-1/4″ deep. Open all 32 pkts (8 oz.) of the Knox gelatin and pour them into a drinking glass. Put exactly 10 cups of hot water into a large stainless pan on the stove. Heat the water just hot enough so you can’t put your fingers in it, about 140F, and TURN OFF THE HEAT. Do not boil! Start stirring with the wire whisk and SLOWLY sprinkle the Knox into the water, a tiny bit at a time. Adding too much at once will make it gum up into balls and you’ll have a useless mess.

Keep stirring. Don’t use an electric mixer because it will put too many air bubbles into the solution. Periodically, use a slotted spoon to remove the foam and scum. It will take 10 or 15 minutes hand stirring to add all 8 ozs, but you can take a break if you need to. After it’s all mixed in, let it set for a few minutes so the fine bubbles will rise and then skim off the rest of the foam.

Now move the pan to the kitchen sink so you don’t make a big mess. To get the clearest gel, use the gravy separator to transfer the solution to the plastic box like this: use a cup to ladle some of the solution from the pan to the gravy separator. Pour off the scum from the separator back into the pan, and then slowly pour the clear solution into the plastic box. Repeat until it’s all transferred. Let it sit on the counter for a while and skim off any remaining bubbles that rise to the surface. Put it in the fridge overnight; do not freeze. BTW, this stuff will keep in the fridge or a cold garage for a couple of weeks, especially if you keep it covered, but will slowly start to dehydrate.



Set-up for shooting:
Here’s the trick. You can leave the gel in the plastic box for all of your shooting by carefully sawing off one end of the box with the hacksaw. You shoot length wise into the open end. Just be careful not to crack the plastic or get a bunch of plastic shavings on the surface of the gel when you are sawing.


I set up a solid rest for my gun and first shot through pieces of cardboard to simulate the front and back end of the gel box. I shot at 8 feet, but closer might be easier. Don’t kid yourself into thinking you’ll be able to aim with the gun sights. Repeatability of the shot location is vital. After you know exactly where your gun will put the pellet, lay a board down flat to hold the gel box at the right height, azimuth, and elevation. I was able to fit nine shots across the 6″ width and make an upper and lower level of shots for a total of about 18 shots. But you have to use reference lines to index the box of gel over a little each time and keep it parallel both vertically and horizontally to the path of the pellet.

Shooting:
Use your index lines to move the box over and/or up or down with each shot. I was only shooting with .177 cal, and found that wadcutters and HPs tended to move the box, so I weighted it down with a clean board before each shot. Domed pellets moved it less. I imagine .22 would make it hop around more, like the .22 rimfires I’ve done the same way. For reference, a Crosman Premier 10.5gr domed penetrated 11.2″ on average.

Photos:
The Custom Cartridge, Inc site has good info about taking photos. Lighting is critical and for me, good sunlight was the easiest way to get good lighting.



Have Fun:
No instructions needed!

28 thoughts on “How to make ballistic gelatin

  1. Sounds like a good project to do while warming up after working on ice dams all day on the roof in upstate NY LOL ! Ok, B.B., request for another topic … the shooting portion of Olympic biathlon competition. I saw a tv show this weekend about the Empire State Games, which is kind of a mini-Olympics for NY state residents, at Lake Placid, and the rifle the biathlon guy was shooting had a very expensive-looking diopter rear sight, so I thought of you and your encyclopedic knowledge of airgunning. Thanks !


  2. Leon,

    Biathlon is usually shot with a .22 rimfire rifle. There are a couple of air rifles made for it, but as far as I know, they aren’t yet used in major competitions.

    Did the announcer say they were shooting with air rifles?

    The diopter sight is the same one found on 10 meter target rifles, only it has a blinder in front that flips up. As I recall from testing a Haenel biathlon rifle, it does so when the gun is cocked. Is that what you mean, or did you see something else?

    B.B.


  3. BB,

    I enjoy your blog, & would appreciate your advice. Don’t know how else to post you.

    I grew up in the sticks, could shoot anything, up to a .12 gauge, from my back porch, no problems.

    Now I live in a neighborhood. I want to get an air rifle to practice/train practical marksmanship – & must train indoors. I’m too old & vision is too poor for competition to be possible. I’d mainly like to be able to take out the chipmonks when I visit my parents.

    What’s the best air rifle to do both, to take out the chipmonks, & to practice for that indoors?

    I don’t care about springs, or cocking, or small CO2 cartridges. They are all OK, but I don’t want to mess with CO2 tanks. Don’t want to pay an arm & a leg, but I have an OK job, love to shoot & don’t mind putting a little money in my hobbies or vices as the case may be.

    Thanks for any help,



  4. B.B.,
    Have you tested the Career Infinity? I purchased one from Pyramyd and must say that I’m disappointed. Not with Pyramyd but with the gun. I’ve bought at least 8 guns from Pyramyd and can’t complain about their service or reliability / customer service. The Infinity is not an inexpensive gun but it came packed like it was a throw away toy. It even had tape on the butt pad covered in stock oil. Really, $39 Crosmans come better packaged and with better manuals! That aside, the gun just won’t shoot. OK, it shoots, just not well. I’ve tried heavy Eun Jin pellets and at 40 yards you’d be lucky to cover a group of 6 with a tea cup. Oddly, the best pellets so far are the JSB Jumbo Express that shoot at 1130-1170 FPS! Supersonic shots are not “supposed” to be accurate but in this gun they do the best (so far). The groups with the JSBs are about an inch at 40 yards provided I’ve filled the gun to precisely 2700 PSI. Any deviation and the groups are more like gatherings… I tried the slightly heavier JSB jumbos and they don’t group well at all. The Barracuda match do a little better but not good. Other than the Drozd, this is probably the least accurate gun I have. I’m hoping you know what the “magic” combination is!
    The overall quality of the Infinity leaves a lot to be desired as well. The receiver is plastic, the barrel clamp is plastic and there is a little plastic muzzle insert that won’t stay put. The gun shot so far right when I got it, I had to loosen the barrel clamp and move the barrel a little to get where I could sight in the scope! I had the same issue with the Dragon Slayer that Pyramyd set up for me. The gun came with the scope adjusted all the way to the right and still shot 2 inches left at 40 yards. Adjusting the barrel clamp (metal on the Dragon Slayer) fixed that (but Pyramyd should have done it before they shipped the “gunsmith set-up” rifle). If I didn’t have the Dragon Slayer (which is very accurate) and only had the Infinity to inform my judgement; I would never recommend buying a Career rifle. Odd that the DS which looks so similar is so much better. BTW, both the Career rifles I own have sticky fill valves. The valves are slow to open and then pop abruptly. Sometimes they don’t want to close and that wastes a lot of air. I only mention these gripes because you can pass them on and Pyramyd has some sway with manufacturers given their volume…


  5. Jerry,

    I’m not sure the misalignment problem can be fixed by Pyramyd. Those guns do shift in transit and the adjustments do get skewed. Pyramyd has been working on Shin Sung for a long time (years) to upgrade their packaging, which is why they recommend a hard case for the gun.

    Now as to accuracy, can you adjust the power lower? You are really shooting too fast for accuracy. Try to get those JSBs moving closer to 900 f.p.s. You’ll also find the Eun Jins tightening if you slow the gun down.

    How about cleaning the barrel with JB Bore Compound? A new arigun often needs it, and yours sounds like it really does.

    As for the sticky valve, that’s typical of careers and some ofther powerful airguns. The valve spring is so strong that the inlet pops open with a metallic twang and the fill pressure drops by about 400 psi when it does. That’s just how the gun works.

    B.B.


  6. On a completly different note, I have an interesting question. I’m patiently waiting for a delivery of my 1st CO2 pistol (Beretta 92FS by Umarex) can’t wait! My question is: Can I use grips made by Hogue or any other manufacture? Has anyone ever had them fit or if not have you tried to “retrofit”? My only choices are black plastic and 1 shade of wood from Umarex. I would really like rubber ones. I’m also interested in getting a pair of Crimson Trace laser grips. Thanks in advance! Keep up the great blog!



  7. B.B.,
    I was going on so long I decided to leave some items out. I’ve been following your advice as posted in this blog and have indeed used the JB Bore compound to clean the barrel. It sure was full of black stuff for being brand new! Unfortunately, I can detect no difference in accuracy after the cleaning. I also got the chrony out yesterday (after cleaning) to see what the actual velocities were. The Eun Jins are leaving at low to mid 900′s and the JSB’s are at 1130-1170 and actually grouping much better! Even if I let the Eun Jins get down to about 800 there is no improvement. They just go wherever! The Eun Jins are good for no better than a 4″ group at 40 yards, the best for the JSB’s is about an inch but that is darn hard to repeat. As a point of reference, from the same shooting spot, at the same target, no more than 2 minutes apart, I’m able to put as many rounds as you’d care to see from my Barnes into a 3/4″ circle. Back to back, I can get the Dragon Slayer to group less than 1.5″ for 6 rounds as well. So I’m confident that it’s not my technique, the cleanliness of the bore or different conditions.
    I wish Pyramyd luck with trying to improve Shin Sungs packaging. Shin Sung should also try to up the quality of the Infinity, I’d buy another DS as it’s worth the price, can’t say the same about the Infinity though. The Infinity ought to be priced about $200 less than it is and sold as a plinker.


  8. Jerry,

    You did everything right. I can’t think of another thing to tell you, except that sometimes other pellets that we don’t usually find to be the best will be the best in a particular gun.

    They are Beeman FTS, Logun Penetrator in both weights and the Crosman Premier. I used to have very good luck with the Premiers.

    Another excellent pellet is the Shark hollowpoint sold by Sunshine Airguns in Miami. I’ve had good luck with them in more powerful rifles like the Infinity.

    Of course if you feel the rifle is not living up to its stated performance, I’m sure Pyramyd will take it back. It wouldn’t be the first time a bad barrel got out the factory door.

    B.B.


  9. On the subject of pellets, has anyone recently bought any Daisy Precision Max .22 caliber pointed field pellets? I ask because I picked up a tin of these last week along with a tin of Benjamin .22 domed pellets for the 392 (nice gun, by the way. I agree with BB on the recommendation.). When I tried to use the Daisy pellets, they would not chamber in the 392 at all. I’ve checked numerous of the pellets and they’re all too large even though they’re marked as .22 caliber. The Benjamin pellets fit and shoot fine. I’ve not used anything other than Benjamins in the gun but I recently ordered a selection of other pellets from Pyramyd to try out. The Daisy pellets were cheap–the only reason I decided to try them. I presume the pellets are defective and I plan on trashing them. Any experience?

    Lee





  10. i bought some daisy wadcutters in .177.
    they were so bad that to this day there are still 400+ of them rotting away, waiting to be used. they wont be, of course. horrible consistency, dented skirts on every pellet, probably half that cannot be shot. worst pellets i’ve ever shot. ever. that includes pellets i salvage (grip one in a vice grip with a bb in the skirt, and sqeeze teh bb in. not very time consuming when you get the hang of it).


  11. B.B., thanks for the post today.
    All the pellets I’ve bought from Pyramyd have been fine, but many of what I have previously purchased at Wally World and a big sporting goods chain have almost seemed like seconds. And that includes Crosman, Gamo, and Daisy being poor quality. I’ve resorted to rolling the pellets on a piece of glass to spot irregularities, and I had to cull out 1/3 of the pellets from one particular tin of Crosman. I’ve given lots of culled pellets to a friend who casts bullets.



  12. B.B.,

    No, the announcer made no mention of the rifle, all he said was bio info on the athletes, how old were they when they got hooked on their chosen sport, etc. The rifle did have a blinder for the left eye that looked to be stationary from shot to shot. The cocking handle was a vertical affair such as on a Logun Gladiator that the shooter pulled back with his right hand, and was very proficient at keeping his sight picture steady while recocking for the next shot. I assumed it was an air rifle from the sound, which was not very loud, but maybe the audio guy had sore ears and adjusted the mic before they shot the footage that aired. Thanks for the reply.



  13. Jerry on your problem with filling your infinity, I went through the exact same experience with my Sumatra(they use the same probe). Believe it or not your problem will most likely be cured once you install a new set of O rings(the newwer O rings are really fat)!
    I ordered extra sets from Pyramyd(the ones found locally did not work). Once installed I have not wasted any air(remember to refill very slowly). What I mean is bad O rings took a fresh fat fill on a scuba tank (3600 psi) down to 2300 psi with just a couple of fills. Which I could never get my rifle filled to over 2700 psi because of all the air leaking out.
    Please note that once you get new O rings installed the only air escaping will be when you are through filling and you open the air release valve on the fill station. This releases all the air in the hose and pressure enabling you to easily remove the fill probe from your rifle.
    I don’t know why you are only filling to 2700 psi–my rifle really likes 3000 psi(the recommended fill pressure). I even had great success at 3600 psi with a 39.5 grain pellet.

    And don’t worry Pyramyd will send you a replacement rifle the day they recieve yours.

    Great Shooting!

    Jay


  14. Okay, I have to take back my comments on the Daisy pellets. I couple of days ago, I picked up House’s “American Air Rifles” book. In the section on the Benjamin 392, he mentioned difficulty chambering some pellets with a sharp shoulder. One of the pellets mentioned was the Daisy pointed pellet. He suggested simply putting the pellet into the chamber manually rather than having the bolt chamber the pellet. Since I had just gotten an order of several different pellets from Pyramyd and was trying them out this morning, I decided to try the Daisy pellets again. As long as I pushed the pellet into the chamber with my finger and finished with the bolt, they fit and function very well.

    I apologize to Daisy for saying their pellets were defective. It seems my technique was the only defective thing involved.

    Lee



  15. Basaltic Gelatin –

    B.B.,

    Does shooting into water mimic fairly closely what can be expected for hollow point expansion in gelatin?

    I also noticed that shooting through a piece of cardboard, or thin sheet of packing polyethylene foam, stops the splash very effectively.

    I was testing my Daisy 22SG and the hollow points just don’t deform shooting into a 5 gallon pail of water. Into a cement slab the pellets flatten entirely. All in all, my testing in water would indicate that 22SG doesn’t have enough power to use hollow points effectively.

    Herb


  16. Herb,

    No, water doesn’t approximate flesh. Crime labs everywhere use water to stop bullets because it doesn’t distort them.

    And you are right, the 22SG is too slow for most hollowpoints to work.

    B.B.


  17. B.B.,

    Bought gelatin and it’s setting up now. In the meantime, I tried a different experiment.

    Krogers had hamburger in a 1 lb. pack that was in a plastic roll about 2.5 inches round and about 6 inches long. Seemed pretty similar to a squirrel to me. I wrapped the hamburger roll in duct tape end over end. I kept one section just one thickness of tape to act as “hide” to shoot through. The rest of the duct tape kept the roll from just blowing apart. The Daisy 22 SG with 5 pumps and Crow Magnum hollow points just blasted through with no real deformation of the pellet at all, same result I got with various experiments into water.

    My Crosman G1 with Crow Magnum hollow points penetrated the hamburger roll only 2 out of 6 times. From point blank range the pellets mushroomed to probably twice the diameter and the head rolled over. I shot the hamburger roll on cardboard over a 5 gallon pail of water so that I could recover any pellets that went though. In separate experiments, by floating polyethylene foam on the water I was able to shoot straight down without getting a bath. The pellets looked very similar to what I shot into the hamburger.

    With a third experiment from 15 yards the Crow Magnum pellets into the hamburger (smashed into a plastic bottle, shooting into end cut open so as to hit hamburger, not bottle) the Crosman mushroomed less so that the head formed a sharp perpendicular edge to the central axis of the pellet (reasonable since pellet would be slower after 15 yards…). Again, the Daisy SG with 12 pumps didn’t mushroom at all.

    When I get a job I may just have to buy a Benjamin Discovery just so that I can get variable power to the pellets. I’d guess that water doesn’t decelerate the pellet quite as fast as flesh, so you have to hit the water a bit faster to get the same deformation. But I’d think that the foam sheet would come very close. The foam “sticks” to the water so there is very little splash back. The surface of the water does ripple, but slashes little. The top of the cardboard separates after the first shot.

    Herb



  18. I use a stack of luke-warm water saturated paper napkins…the common four-fold kind of sturdy construction like Bounty. After soaking, the stack can be stood on end, still in the plastic wrapping, then the other end. This lets it compress evenly a bit under its own weight and the excess water squeezes out. Then I lay the whole thing back down flat to shoot a shoot a BB at about 600 fps into it. I used a piece of wire to probe the depth. If the BB penetrates between 3-1/4" and 3-1/2", I consider it "calibrated" the same as the FBI does with gelatin. Too deep? Compress the stack some more. Too shallow? Add water and let the stack re-expand a bit. Before testing pellets I cover the shooting side with a couple layers of denim or a thin piece of leather from an old glove to simulate animal hide.



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