Ballistic gelatin is a solution of gelatin powder in water. Ballistic gelatin closely simulates the density and viscosity of human and animal muscle tissue, and is used as a standardized medium for testing the terminal performance of firearms ammunition. While ballistic gelatin does not model the structure of the body, including skin and bones, it works fairly well as an approximation of tissue and provides similar performance for most ballistics testing.
Ballistics gelatin was introduced to the general population by the television shows MythBusters and CSI: Crime Scene Investigation, which show ballistic gelatin used in such a capacity. MythBusters uses ballistic gelatin, sometimes in the form of a dummy named ‘Ted’ (as in bus-Ted), for the widest range of purposes, testing not only bullets but also the lethality of pennies at terminal velocity and Kleenex boxes at highway speeds, the damage CDs can cause, and even electrocution.
I plan to mix up sufficient amounts of ballistic gel, and create a target to fire at with my air gun. From there, I can measure the projectile’s penetration into the gel, which is the equivalent of the penetration the projectile when it is fired at a human body.
Difficulty: 1 2 3 4 5 6 7 8 9 10
Cost: 1 2 3 4 5 6 7 8 9 10
Time: 1 2 3 4 5 6 7 8 9 10
1. 100% Gelatin Powder
3. Machine Stirrer
4. Plastic Container/Mold
Ballistics labs within the FBI and law enforcement often use ballistics gel to test wound penetration. They use a special ordnance gelatin powder to make the gel to specific standards under carefully controlled conditions, and it is then calibrated for accuracy. I lacked the time and facilities to prepare the gel to FBI standards, but I hope to produce a reasonable homemade version that has a decent accuracy.
Ideally it is advisable to use gelatin powder made specifically for ballistics use, which is manufactured by Kind & Knox. However, the powder has to be special ordered in bulk and is expensive.
A cheaper version for household usage is available in US supermarkets, but I couldn’t find it in the two Singapore supermarkets I went to.
So I settled for the only one I could find at NTUC, a Singapore-brand one. I bought 4 of these.
Well, I do understand that ‘Bake King’ isn’t the best name of gelatin brands out there, but I had no choice.
Ballistic gel is prepared by having a 10% proportion of gelatin to 90% of distilled water. This produces a very thick gel. The 200g of gelatin powder I bought is supposed to mix with 1800ml of water, however, I was amazingly blur and foolish. For some reason I have still yet to uncover, I used proportions of 14% gelatin. The gel is much harder, and feels really tough. Also, the gel is kept constantly chilled as far as possible, and only removed from the refrigerator just prior to shooting. I ended up with a ballistic gel that is TOO tough. I only realised this after the experiment and looking through the pictures, so let’s just make do with it.
I measured the gelatin:
And the water…
I heated it to about 60′C. The temperature of the water shouldn’t be over 65′C. A 1988 research paper recommends that the water should not be heated above 40 C (104 F), as this can cause a significant change in the ballistic performance. However, MythBusters recommends 60′C, and I’ll just stick to MythBusters’ measurements.
Machine stirring is almost mandatory, so I used this.
And with the water spinning inside, I slowly added the gelatin powder.
I just left it alone to mix well for a good couple of minutes or so.
When everything looks good, have the gelatin removed and you’ll see that there’s a lot of bubbles and foams all over the surface. These bubbles and foams will solidify along with the gelatin if you leave it there, so it’s neccessary that you remove them. I used a spoon to scoop the bubbles and foams off the surface.
Next, find a plastic container which is suitable as the mold.
Then pour the gelatin inside, leaving it in the refrigerator to solidify.
Depending on the amount of gelatin, a good 2 days would suffice. After that, you can remove the gelatin from the mold.
I used a knife to dig the sides out.
And the preparation is completed!
Take note that I actually made two different samples of ballistic gel.
This is the first attempt at making the ballistic gel. The mistake made here was that the gel was not kept constant at 4′C, so it’s softer than ideal.
I had a setup for the shot in the, er, let’s just call it attic of my house.
With the small piece of gel mounted on top of a Styrofoam piece, with a cardboard backing, I stood about 3m back. The airgun was pressured to 60 PSI.
This is the aftermath of the shot.
Note: The ballistic gel closely represents human flesh. However a mistake was made. The ballistic gel was not kept at a constant 4 degrees centigrade environment. This makes is slightly softer than the ideal ballistic gel.
The projectile FULLY penetrated the 8.5 cm thick of ballistic gel, plus three layers of hard cardboard.
If you’re thinking that isn’t enough to kill, you’re either Wolverine or a liar.
The metal rod penetrated so deep into the cardboard that it took a lot of trouble to get it out. I pulled hard, and all that came off was the rubber backing.
This is the metal rod with the rubber backing pulled off. You can see the damage caused clearer here.
This is the second attempt of the ballistic gel. While it was kept constantly refrigerated until just prior to shooting, a wrong proportion of 14% gelatin was used. Thus, the gelatin is tougher than desired.
The airgun was pressured to only 25 PSI because my air pump was spoilt. As this was merely a small test fire at 25 PSI, I didn’t bother to take videos and pictures. But I got these:
I measured the penetration of the projection, and it’s about 3.2 cm.
Once again, please be reminded that the ballistic gel is supposed to closely represents human flesh, and in fact, it’s much tougher.
After this, I decided that I will not do any further testings because it’ll simply be wasting money to purchase another air pump. I’m setting for the 25 PSI shot and do further estimates from there.
At 25 PSI, it achieves a 3.2 cm. At its full power (limited by the air pump I buy) of 80 PSI, it should be at least 3 times as powerful, thus achieving a penetration of 9.6 cm at least. Of course, this are just estimates, and are definitely by no means, accurate. However, the true figure should linger near that value, possibly less.
To conclude, the airgun, fully pumped to 80 PSI by the air pump, would be able to penetrate at least 9.6 cm of human flesh using the projectile I made. The ballistic gel used here is 14% gelatin instead of 10%, which makes it significantly tougher than the 10% proportion.
If this isn’t enough to kill, I don’t know what is.
I needed to remold the gel after the test shots.
So I did what I usually do: Place the gel into a pot, heat it, and pour the molten gel into the mold.
Well, it sure was melting, but at an incredibly slow rate. So I left it there.
For a short while only, really.
And after that short while, I came back to smell something horrible.
It was this:
I, amazingly, managed to burn MOLTEN gel.
I mean, it was all black. And it smelled real bad.
And so there you have it, my $9 spent in ballistic gel, along with lots of time, got toasted in its liquid state.
I shall spare you the more disturbing details of the clean up, which took like say, 45 mins? The gel solidifies at room temperature, so you get the idea.
Because of this unfortuntae incident, I wouldn’t want to spend another $9 on gelatin again. I’ll stop with the testings here.