Attorney Tom Grieve, a former prosecutor turned defense lawyer, recently raised a question that sits at the heart of every concealed carrier’s decision: do you carry enough gun for self-defense? In his breakdown of caliber studies and real-world shootings, Grieve challenges the popular idea that bigger always equals better. He argues that shot placement, psychological responses, and legal preparedness may matter more than obsessing over caliber size alone.
The Myth of the “One Shot Stop”
Grieve began by dismantling the Hollywood fantasy of the “one shot stop.” Movies show attackers collapsing instantly from a single bullet, but Grieve explained that real-world data tells a different story. Citing Greg Ellifritz’s decade-long study of more than 1,700 shootings, he noted that the average defensive encounter required closer to two rounds to bring an attacker down. Even then, accuracy rates among armed citizens hover between 23% and 30%. In other words, people miss more often than they hit, making magazine capacity and follow-up shots far more important than a mythical one-bullet solution.
Why Attackers Really Stop
Grieve separated the concept of stopping power into two categories: psychological and physiological. According to him, psychological stops are by far the most common. That’s when an attacker chooses to stop after being hit – not because the bullet physically incapacitates them, but because they don’t want to get shot again. Grieve stressed that in many shootings, attackers essentially give up rather than collapse from catastrophic injury.
Physiological stops, however, are different. These require either disruption of the central nervous system (brain or spinal hits) or rapid blood loss. Even then, Grieve warned, someone shot through the heart may have 12 to 15 seconds of fight left in them before losing consciousness. That window can be more than enough for them to inflict fatal harm.
The Role of Shot Placement
Grieve emphasized over and over: placement trumps caliber. Headshots led to immediate incapacitation in about 75% of cases, while torso shots, though much easier to hit, worked around 41% of the time. Extremity hits were almost useless, with just a 14% immediate stop rate. His conclusion was blunt: a .22 to the brain is more effective than a .44 Magnum to the hand. Accuracy, not raw power, carries the day.
Comparing Small and Large Calibers
To simplify his analysis, Grieve grouped calibers into two categories. Small calibers included .22, .25 ACP, and .32 ACP. Larger calibers included 9mm, .38 Special, .40 S&W, and .45 ACP.
He explained that small calibers often appear to perform similarly to large ones when looking at psychological stops. But when psychological surrender fails and an attacker presses forward, the weakness of small calibers becomes obvious. Their failure rates nearly doubled compared to larger cartridges, leaving defenders with less margin for error if they needed a true physiological stop.
The “Big Four” Defensive Calibers
Among larger calibers, Grieve pointed out how surprisingly close the data was. The 9mm, .38 Special, .40 S&W, and .45 ACP all fell within a narrow band of effectiveness. One-shot stop rates ranged between 34% and 45%, while failure rates clustered tightly between 13% and 17%. His takeaway: switching between these four calibers doesn’t drastically change the outcome. Whether you carry a compact 9mm or a full-size .45 ACP, statistically, you’re about as well equipped.
The Practical Advantage of Bigger Cartridges
Where larger calibers shine, Grieve explained, is when psychological surrender fails. If an attacker is determined, drugged, or mentally unstable, the heavier bullets of the “big four” calibers provide a better chance of causing a physiological stop. That doesn’t mean small calibers are useless, Grieve admitted any gun is better than none, but he cautioned against believing that a .25 ACP pocket pistol is “just as good” as a 9mm.
Accuracy Rates Don’t Favor Small Guns
Many shooters claim they carry smaller calibers because they shoot them more accurately, with less recoil and quicker follow-ups. Grieve pushed back on this argument. Ellifritz’s data, he explained, showed no meaningful accuracy difference between calibers. Whether people carried small or large handguns, their hit rates on vital zones were about the same. That finding reinforces his broader point: training, not caliber, determines accuracy.
The Importance of Capacity
Grieve also reminded his viewers of the realities of human performance in a fight. With only about a quarter of shots landing on target in most defensive shootings, low-capacity guns leave you dangerously underprepared. A small-caliber single-stack pistol may hold only six rounds, which could translate to just one or two hits. By contrast, even subcompact 9mms now carry 12–15 rounds, greatly improving the odds that enough shots land in the right place.
The Real Stopping Power
Grieve summarized the data with a sobering conclusion: caliber isn’t irrelevant, but it’s far less important than skill. A defender who trains regularly, understands shot placement, and carries enough ammunition is far more likely to survive than one who simply bets on a “powerful” caliber. The real stopping power lies in fast, accurate hits delivered under stress – not in the size of the bullet alone.
The Legal Side of Carrying Enough Gun
One of Grieve’s strongest warnings had nothing to do with ballistics. He urged carriers to develop legal competency. In his words, it’s no victory to survive a deadly encounter only to lose everything in court. He reminded viewers that every bullet fired carries legal consequences. Knowing the law, understanding when you can and cannot shoot, and preparing for the courtroom aftermath are just as important as caliber choice.
No Shortcuts
What struck me most about Grieve’s analysis was how it pulled the teeth out of caliber wars. For years, shooters argued endlessly about 9mm versus .45 ACP, or whether .40 S&W still had a place. The data suggests those arguments miss the point. The critical variable isn’t the size of the round – it’s the accuracy of the shooter and the willingness of the attacker to quit. To me, that’s both comforting and sobering. It means almost any modern defensive caliber works, but it also means there are no shortcuts. You can’t buy skill in a box of ammo.
A Balanced Closing Perspective
Grieve closed his talk with an Aristotle quote: “We are what we repeatedly do. Excellence then is not an act, but a habit.” It’s a fitting conclusion. Caliber debates will never end, but carrying enough gun is about more than size. It’s about developing habits of practice, discipline, and legal awareness. Whether you carry a snub-nosed .38, a compact 9mm, or a full-size .45 ACP, the responsibility is the same: train hard, shoot straight, and know the law.
Mark grew up in the heart of Texas, where tornadoes and extreme weather were a part of life. His early experiences sparked a fascination with emergency preparedness and homesteading. A father of three, Mark is dedicated to teaching families how to be self-sufficient, with a focus on food storage, DIY projects, and energy independence. His writing empowers everyday people to take small steps toward greater self-reliance without feeling overwhelmed.
