On a few occasions I have been asked by incredulous gun curmudgeons why I waste my time, energy and money on terminal performance testing. After all, manufacturers of ammunition and reloading components publish an endless stream of ballistic data on their products detailing trajectories, muzzle velocities, and kinetic energies. The naysayers also point out that manufacturers generally conduct extensive terminal performance tests of their own and that my own backyard endeavors are likely redundant exercises.
The short answer is, while I could spend endless hours on the internet compiling data from tests that have already been conducted by others, I find it’s much more fun and rewarding to conduct tests myself. Terminal performance testing is a hobby in and of itself.
Admittedly, part of the appeal of terminal performance testing is simply a fascination with what happens to materials when they are subjected to extreme conditions. The same personality traits that drew me to melt glass bottles in campfires as a child drew me to fire bullets into soft media as an adult. Shooting is fun and so is examining recovered bullets and damaged test materials.
The results obtained through such informal testing are also useful since the math associated with a given round is not necessarily indicative of how it will perform when it hits an organism. Projectile diameter, projectile composition, and even projectile shape can have a tremendous influence on how the projectile performs after it impacts a target. It therefore makes sense to test such projectiles by firing them into a material that closely approximates what they will be used on during real world application. In the case of hunting and most personal defense ammo, such a test media should be something soft but of sufficient density to approximate organic tissue.
Non-professional ammo testers traditionally employ a variety of test materials to accomplish their goals. Each of these has advantages and disadvantages. The following are some of the media options available to the backyard ballistician and a summary of my experience with each.