Everything You Need To Know About Ballistics Gel

So, let's talk about ballistics gel and why it is that ammunition is tested in it. The stuff is basically what you think it is: it's more or less a big block of Jello that people shoot.

Is it worth paying attention to when someone posts up pictures or video saying they just sent some .22 Magnum or some hot new 9mm load through it?

It actually is, but you need to be aware that ballistic gelatin is not a perfect medium by any means. However, if you know a little more about it, hopefully you can understand a little more about why it's used and why it's useful.

What IS Ballistic Gel, Anyway?

Like so many other things, "ballistic gel" can have a number of different meanings.

In most instances, it means a block of solid gelatin that's used for the purposes of studying terminal performance of ammunition, including penetration, expansion, stretch cavities and permanent cavities created by bullets hitting a not-quite-solid medium.

In other words, what you'd use to test 10mm vs 9mm.

There are also specialized gel products out there that are made solely for the purpose of ballistic gels, such as clear ballistic gelatin. They aren't the ONLY type of gel useful for the purpose, which is something we'll get to later.

Make sense?

Alright, now the question becomes just what ballistic gel is made of.

Ballistic gelatin essentially breaks down into two categories: synthetic and natural.

Synthetic ballistic gelatin is made with man-made (ie not natural) chemicals, which is typically how you get the clear stuff.

Then you have natural ballistic gel, which - DUH! - is made of natural ingredients, either plant- or animal-based.

You might be wondering what the difference is between ballistic gel and plain food gelatin is, like what you might use to make fruit cake, head cheese, or something along those lines. And the answer is…

There isn't any. You can literally do ballistics testing with the same gelatin in the baking aisle of most grocery stores. Composition is not actually what's important, which we'll cover shortly.

What Is Ballistic Gel Made Of?

Ballistic gel, well, is gelatin, and gelatin is gelatin.

What IS gelatin?!

Gelatin is collagen that has been hydrolyzed, meaning all water has been removed - and this is the Reader's Digest version, so just bear with the glossing over of many details - by means of subjecting collagen to electric current, which separates water from the other elements.

Collagen is a type of protein, composed of a mixture of amino acids, found in most connective tissues in the body. It's formed by amino acids branching together to form fibrous, helical strands in connective tissues of the body such as tendons, ligaments and skin. It's very tough, but also pliable.

Oh, heck. Here's Alton Brown to explain:

Have you ever eaten ribs that weren't cooked long enough? You know how you have to practically rip the meat apart with your teeth, and there are little bits stuck in your teeth for days? That's collagen! Gelatin is that stuff rendered into a powder, then mixed with water and allowed to set.

Unless it's synthetic, in which case it's synthetic amino acids that likewise absorb water and bind together when emulsified in water.

Wait...Does That Mean You Can Make DIY Ballistic Gelatin?

Yup. DIY ballistic gelatin is literally the same as the stuff they use in labs if you make it right.

Making your own ballistic gel is actually very easy. You literally combine unflavored food gelatin with water until it sets. Then reheat to liquify it and pour it in a mold to make a block.

The amount you'll need to use depends on the size of the mold. Again, to make 10 percent gelatin, you need 1 part powdered gelatin to 9 parts of water; if the mold requires 6 quarts, which is 192 ounces, you'll need 19.2 oz by weight of powdered gelatin. Which stinks, because you normally buy it in 16 oz (1 lb) tins if you aren't buying the little 1 oz packages.

Ballistic Gel Density

So, the density of ballistic gel is determined by the ratio of powdered gelatin to water. More gelatin, a denser block after it sets in the mold.

The standard densities are referred to by the percentage of gelatin that's used to make the block. Typical ballistic gel formulas are 10 percent and 20 percent, which - respectively - are 1 part gelatin to 9 of water, or 2 parts gelatin to 8 of water respectively.

Again, you can make this stuff at home and do your own ballistic testing. Seriously. As you can tell, it isn't hard; it's literally a recipe with two ingredients. If you've made mac and cheese from a box, you can handle making gelatin.

At some point, someone is going to mention the FBI protocol. The FBI ammunition testing protocol, first devised in the wake of the 1986 Miami shootout, calls for the use of 10 percent ballistic gelatin, according to American Rifleman, and for the projectile to penetrate 12 to 18 inches of gel, both in bare gel, through clothing, and after passing through barriers.

So, anyone using 10 percent (by weight) ballistic gelatin is using the same ballistic gel that the FBI does, and the FBI standard - for better or worse - is one of the best predictors we have when it comes to ammunition performance in the real world.

Why Ballistic Gel Is A Good Testing Medium

Ballistic gel is used as a testing medium for ammunition because of two key properties, namely that it has both elasticity - the material stretches - and because the person doing the testing can control the density of the testing medium by virtue of either making the gelatin themselves or purchasing gel blocks of the desired density.

Now, we mentioned that it isn't a perfect testing medium. Here's why:

The human body, obviously, is not comprised of homogenous tissue. There's skin, muscle, sinew, bone, blood and other fluids, organs, fat, etc. Gelatin, however, is a homogeneous material; it's the same composition, density, hardness and so on throughout. Therefore, it's obviously not an apples to apples comparison, is it?

Why is it used?

Since the human body is composed of a number of different tissues and materials, all with different densities, what you can do with gelatin is make it to the average density of those tissues.

People who test this stuff professionally came to that conclusion years ago, which is why ballistic gelatin has become the testing standard instead of some other material.

Again, it's not perfect. However, ballistics gelatin is a good testing medium for terminal performance of ammunition because it simulates the average density of tissue in a fleshy target. In the fullness of time, however, what's been found is that there's a correlation between performance in gelatin and performance in police and civilian-involved defensive shootings.

In other words, ammo that proves itself in the lab, using testing protocols for defensive ammo, TENDS to perform on the street. Likewise, hunting ammunition that performs in the lab tends to perform in the field. Until someone comes up with a better way to test and predict ammunition performance, it's pretty much the best thing we have.