‘There were over thirty of them in continuous action, and all I could do was touch the Germans off just as fast as I could. I was sharpshooting. I don’t think I missed a shot. It was no time to miss.’
-Alvin C. York’s account of October 8, 1918
For Walkthrough Wednesday, we are starting a discussion on a topic that is commonly misunderstood and appreciated: we are going to begin a conversation on ballistics. Reference for this is Appendix B, TC 3-22.9, Change 1 dated January 2017.
Ballistics is the study of a projectile in motion. TC 3-22.9 defines it as “Ballistics is the science of the processes that occur from the time a firearm is fired to the time when the bullet impacts its target [and ceases movement].” Put simply, Ballistics is everything that happens the moment the firing pin comes in contact with the primer, to just before the projectile ceases movement in its target.
There are three major categories of ballistics: Internal, External, and Terminal. Internal ballistics are everything that happens to the projectile from the moment the trigger is squeezed to the moment before it exits the barrel. External ballistics is everything that happens to the projectile from the moment it exits the barrel to just before it impacts on its target (whatever it happens to be), and Terminal ballistics are what happens to the projectile from the moment it enters its target, to the moment before it comes to rest.
Knowledge of Ballistics is traditionally associated with Snipers and Squad Designated Marksmen, with the subject considered too advanced for the common Paratrooper to understand. However, it is just as important for Leaders and Paratroopers to understand the different categories of ballistics. It can help a Paratrooper to diagnose what malfunction is taking place with the weapon in the case of internal ballistics. It can help to ensure a probability of hit based off an adjusted point of aim off Center of Visible Mass, also known as a hold in the case of external ballistics. And it can help to ensure the highest probability of placement into an area that will incapacitate the enemy by switches and timers, in the case of terminal ballistics.
The category that has the greatest impact on whether the projectile will hit or miss the Paratrooper’s intended target is External Ballistics. External Ballistics is comprised of Gravity, Drag, Wind, Altitude, Humidity, and Temperature. Some of these factors, such as gravity, are constants, and thus have a consistent effect on the projectile. Many of these factors are variable. Altitude, drag, humidity, temperature, and wind, all vary from shot to shot, so it is important that the Paratrooper understand what kind of an effect this has on their projectile so that they can account for it.
So to sum up, Ballistics is the study of projectiles in motion. There are three major categories of ballistics: Internal, External, and Terminal. It is important for Paratroopers and leaders to understand ballistics, so that they can compensate for the various effects they have on either the projectile or the weapon. And the Category that has the greatest effect on the projectile’s intended path is External Ballistics. Next week, we will discuss various terms that are associated with ballistics.