Few topics can light up a range-side or gun store discussion like handgun caliber. Most every long-time handgun owner feels strongly about one caliber or another being the best. When speaking of defensive use, the term “stopping power” almost always enters the discussion. Is there a best caliber for self-protection? This article looks at both professional opinion and conventional thinking to answer that question.
For purposes of framing the discussion, we’re talking primarily about the differences between two common choices for a defensive handgun: 9mm Luger and 45, whether it be the ACP, Long Colt, or any other sub-category of 45.
What Is the Goal of Defensive Shooting?
To defeat a common myth from the start, defensive shooting does not have killing as its purpose. The sole purpose of a lawful self-defense shooting is to stop the attack. Despite what movies and TV would lead us to believe, only one in six people who sustain gunshot wounds die. Also counter to typical media portrayals, a single round fired from any caliber handgun has less than a 25 percent likelihood of stopping an attack. Odds go up substantially—to about 63 percent—with two shots.
It’s important to distinguish defensive ammo—including hollow point, jacketed hollow point, and newer variants (HP)—from target ammo, typically with full metal jacket (FMJ) bullets. In any caliber, FMJ is made to penetrate and cruise on in as straight a line as its speed and mass will permit. HP is made to expand in size, and sometimes fragment into smaller projectiles, after a certain distance after impact with solid tissue. The wider the expansion, the more dramatic the fragmentation, the greater the would channel and the more “stopping power” might be conferred upon the round, under ideal conditions. By ideal conditions, I’m referring to a center mass shot on a typical 12-14-inch thick critter, whether two-legged or four. Miss slightly, and that round may sail through muscle and exit the other side, perhaps not even slowing down the subject.
Performance of the smaller calibers like 9mm and .380 ACP HP has come a long way in recent years. Loads once considered insufficient for penetration of clothing and fat are better dialed-in for personal defense. Lots of shooters like 45 for the confidence-producing big hole it makes. But in some cases, this slower-moving projectile (typically around 850 feet per second as compared to in excess of 1,000 fps or more from 9mm), can produce less penetration and fragmentation.
It could be said that HP is a responsible selection of ammunition for the self-defense handgun as compared to FMJ. It’s been made to expend its energy on the first thing it meets, and is less likely to sustain velocity and cause damage beyond the intended target (need I say again under ideal conditions, which only exist in the laboratory?).
A good strategy is to check out your ammo manufacturer’s website where ballistic data can often be found, or even YouTube videos where some producers have gone to the trouble to re-create FBI protocol gel block tests.
What Matters More Than Caliber?
We’ve established that a handgun is a relatively weak weapon against a mammal like the typical human being. Permanently etched in my own memory are two grown men whom I met with in the emergency department in connection with my work, both of whom had been shot in the skull—one with 40 S&W and one with 9mm. Both had wounds that started on the side of the head and, rather than penetrating, the bullet had followed the curve of the skull until it got around the side, behind the ear, and simply went on its way. Both individuals had nothing more than minor scalp wounds. A look at war photos online will show an astonishing (but gruesome) selection of photos of soldiers who survived shots to the lower half of the face.
Anyone who’s studied defensive shooting much knows that it is only a round through the brainstem or upper spinal cord that guarantees an instant stop. In all other cases, including an eventually round right through the heart, the continuation of the attack depends on the determination of the attacker.
Shot placement, followed by a sufficient number of rounds to deflate the assailant’s determination or physical capability, is far more important than caliber.
Decide What’s Right for You
Knowing the above, I prefer to carry something that offers more rounds in the gun, as well as an extra magazine, discreetly riding in a pocket. For me, navigating daily life, that means 380 or 9mm. While I admit there is greater “oomph” in the 40 and 45 loads, the former of which I carried for years and still do on occasion, it is my present and usual choice to carry something that holds more ammunition and is instantly accessible in my waistband.
When you’ve learned how your selected rounds perform in terms of expansion, penetration, and so on, compare that to your likely defense scenario. For example, if you’re being stalked by a 350-pound behemoth or live in a region where people wear heavy layers of clothing most of the year, the .380 may not have sufficient penetration to be effective. Comfort will play a factor, as well. If you can fit your favorite 45 into a concealment rig, have at it. Many people can’t make that work. Choose something you’re confident about in terms of performance, as well as something that is wearable. The coolest or most beloved handgun, left behind because it’s too big, can’t help you defend your life.
What is your favorite caliber for self-defense? Share your advice in the section below: