Understanding bullet impacts
Terminal Ballistics – Part I is the first in a two-part series which will begin to conclude the Ballistics Series by introducing the principles within Terminal Ballistics and focus on the various aspects of projectile impacts on target and their immediate effects. Leveraging the key concepts of projectile flight and construction, momentum and kinetic energy introduced earlier in the ballistics series, this article will illuminate some scientific facts in regard to the terminal effect of firearm employment for hunting, law enforcement and personal defense while also debunking some commonly-held myths. In researching this topic, I’ve relied heavily on authoritative sources such as Robert Rinker’s “Understanding Firearm Ballistics, 6th edition,” and the Federal Bureau of Investigation’s 1989 report titled “Handgun Wounding Factors and Effectiveness.”
Whether for recreation, competition, training, hunting or personal defense, this ballistic series has focused on the myriad of aspects that affect a projectile’s flight to target in order to provide a better understanding and help you choose the right firearm/ammunition combination to safely and consistently place your shots on target and achieve the desired ballistic effects. From the mechanical interactions internal to the firearm to the atmospheric and physical conditions that affect projectile flight, this series has provided information necessary to harness mechanical precision into shooter accuracy. Now, we will discuss projectile impacts on target.
Since recreational and competitive shooters are primarily focused on measuring the effectiveness of their skill and technique by scoring shots on paper, cardboard, or interactive targets, terminal ballistics is simply a factor of hitting the target for score. For hunters, military/law enforcement, and personal defenders, on the other hand, the projectile’s ultimate effect is eminently important since it is the sole reason for weapon employment. Although the conditions for weapon employment are much different in these latter cases, the desired result is the same… rapid incapacitation with as few shots fired as possible!
This rapid incapacitation is a factor of shot placement combined with velocity, kinetic energy, projectile weight, projectile shape and construction, caliber, and range to target as well as the nature of the target itself. In order to move forward with the discussion, we need to first discuss some terms and concepts common to both hunting and personal defense.
Terms and Concepts
- Caliber – diameter of a projectile
- Mass – in the most general terms, this is the weight of the projectile
- Velocity – this is the instantaneous speed at which the projectile is moving. Projectiles exit the firearm bore with an initial velocity which immediately begins to slow down due to air resistance and drag.
- Ballistic Coefficient – based on the shape and construction of the projectile, this number describes how well the projectile travels through the air and preserves its velocity. Read More »
Howard Hall – Range Master
Howard has served for nearly 20 years in the Marine Corps. He has served as a Platoon Commander, Company Commander, Battalion Executive Officer, Regimental Operations Officer, and Battalion Commander. He has multiple combat tours to include serving as a military transition team member in Fallujah. He is an NRA Certified handgun instructor and holds numerous Marine Corps training credentials. An active competitor in action pistol (United States Practical Shooting Association), long range rifle (NRA F-Class), and shotgun (Amateur Trapshooting Association, National Skeet Shooting Association), howard has earned numerous accolades and medaled during DoD competitions with the 1911 platform in bulls-eye shooting.