PROJECTING HANDGUN EFFECTIVENESS FROM ACTUAL ENGAGEMENT RESULTS (Oct 2024)
Go straight to Stopping Power Calculator
Over a decade ago, Greg Ellifritz published a veritable treasure trove of real-world data from about 1500 law enforcement and military handgun engagements, but I came across it just recently. And Evan Marshall published summaries of some 7000 engagements years earlier. Unfortunately, the popular formulas used over the years to try to predict handgun effectiveness didn’t even remotely conform to their real-world data. One of the more powerful techniques I used as a defense-industry combat-effectiveness analyst to predict the performance of various upcoming weapons systems was curve fitting. We employed it to help the U.S. government and defense companies decide what new technologies held the most promise. Curve fitting takes field data from mature, real-world systems and applies statistical methods to develop a mathematical “curve.” A curve is simply a formulaic set of datapoints that essentially matches the empirical data.
I used curve fitting to establish a formula that mirrored Greg’s & Evan’s real-world data. It turned out to be one of the tightest curves I’ve ever generated, and I believe it’s quite solid (so much so that I used it to guide a recent purchase). I’ve also used it to project the incapacitation effectiveness of a few handgun calibers not covered in their dataset. The graph below shows all the handgun calibers I’ve assessed with the formula (so far). You too can go to the Calculator (link below) to make your own assessments for a new caliber or for a specific round for a particular caliber. That’s the power of curve fitting. (If you want to know how I arrived at the numbers and why I’m confident in the results, please watch the videos below).
Why is handgun effectiveness addressed on a site dedicated primarily to practical theology?
The answer is two-fold:
1) Finding our present purpose in our true eternal mission doesn’t mean we’re suddenly exempt from our responsibilities in this broken world. In fact, the opposite is true; that knowledge should increase our sense of duty in our current arena (not only spiritually, but physically was well). As biblically-informed people, especially men, we have a God-given responsibility to be protectors of those in our spheres of responsibility.
And 2) I feel extraordinarily qualified to bring new insight to the subject of handgun incapacitation effectiveness. I have a decades-long background in professional combat-effectiveness analysis that was uniquely critical for the study conducted here. I’m also a one-time police officer and a recipient of the U.S. Navy’s Expert Pistol medal.
