Stopping Power, What Caliber Should You Carry?

| Last Updated:
October 2, 2023

What Caliber Should You Carry for Optimal Stopping Power?

If you ask five people this question you will probably get five different answers. This question seems to encourage a somewhat opinionated answer. It also tends to be a somewhat controversial topic. Is there even a correct answer?  In my quest to answer this with the most accurate evidence-based information possible, I have come across a lot of history into why this is such a hard question to answer. Let’s first look into a few facts.

Stopping Power: What is it and Does it Matter?

The answer to “Is there even such a thing as stopping power?” is in itself somewhat misleading. If you look up the definition of stopping power, Wikipedia will tell you that it has to do with a bullets ability to stop or incapacitate a target. It does not necessarily relate to its force but instead its ability to do enough damage to prevent the target from advancing, therefore, equaling stopping power. This is different than how lethal the weapon may be but instead is directly related to whether the target will continue advancing after being shot. 

Caliber vs. Stopping Power

If you were paying attention, then you have already realized that force does not necessarily equal stopping power. To further muddy the waters, all calibers have been found to have the ability for one-shot stopping power in the right circumstances. Even the lightest and heaviest of calibers have real-life situations where this has been proven.

One-shot wonders have been statistically documented from many decades by book authors Evan Marshall and Edwin J. Sanow in multiple books. To be included in the statics, the shots had to meet certain criteria, such as only counting torso shots, only counting attackers that stopped attacking or shooting, and only allowing for a set amount of travel once a round was shot.

Realizing that headshots in an attack situation are unlikely and that most people are trained to shoot for center mass, it only makes sense to take out headshots as part of the comparisons. Keep in mind when referencing these statistics, I’m referring to stopping power as a single shot to center mass that results in incapacitating a target. Not even extremity shots were counted, even if it achieved the same outcome of stopping an attacker.

Now, let’s throw out the one-shot wonders. What? Yes, forget about them. Why even bring them up, you ask? They do happen, but it's not the norm. Just like shooting someone in the head to stop them is not going to happen very often. The idea behind shooting for center mass is to give you the best chance of hitting a target under stressful conditions. Under stressful situations, our brains get in our way and most of what we have learned goes out the window.

For most of us in this kind of situation, we go into lifesaving mode with adrenaline pumping and forget most of what we know to do. This is partly why there are two very simple, but important, techniques to remember. Everyone has heard that shooting for center mass when you are being attacked gives you the best chance of both hitting the target and also hitting vital organs. However, this is only part of the equation.

The second part is to continue shooting. If you have to shoot to stop an attacker, keep shooting until that threat stops. Most attackers will not be stopped in one shot, so this rule and real-life technique to live by changes everything. How many attackers would have been stopped with only one shot? It is impossible to say. If an attacker keeps advancing, then the rule to live by is to keep shooting. Attackers that have been shot multiple times before they stopped do not count toward the one-shot stopping statistics, even if they would have only traveled a few more feet before dropping. There is simply no way to know statistically how many attackers would stop after one shot.

Is Stopping Power Even Real?

I have a background in science. To me, stopping power is a measurement of a material or a force’s ability to stop energy or a median’s ability to absorb energy. If we apply the same concept, then we can come up with a measurable, repeatable outcome. In this case, we could depend on ballistics testing to decide exactly what to carry, but the testing on materials cannot be applied to people.

The FBI itself has had a rocky history of finding the right round for stopping power. In the 80s, a famous shoot-out with the FBI occurred where bank robbers were actually hit by at least 12 shots before going down. The FBI decided that they needed a more powerful handgun. At this point, the FBI decided to try out the 10mm, 40 caliber round.

What they found is that the gun itself made it difficult to shoot follow up shots accurately. After this, they decided they needed a less powerful round and went to the 10mm light load. Ultimately, they landed on the 40 caliber by S&W which was used for over 20 years. Guess what? In 2018, they went back to the 9mm. Mostly this tells me that if the FBI can't decide, the answer is that there is no perfect round.

What Caliber Should You Carry?

The most accurate answer is probably not what you want to hear. If you truly want to know what you should carry, then you need to figure out what Is best for you, not me. If you are excellent at making your first shot but the recoil makes your second shot nearly impossible, then you have a problem. In a shoot-out, it’s estimated that more shots miss, than hit, the target.

Here are some things to consider:

  • Is your weapon a size that you can handle day in and day out?
  • Can you effectively train and carry your gun?
  • How many bullets do you need to carry to be able to stop a target?
  • What are you most accurate with when firing multiple shots in a row?

The Caliber Doesn’t Matter

When I started researching this topic, I had my mind made up. I assumed the more powerful the gun the more likely you are to stop a target. I quickly found out that my reasoning simply didn’t make any sense. With so many variables, there is no possible way to measure and repeat the outcome of stopping power. So, I have to agree with the FBI, stopping power is a myth.

Michael Lutes

Michael Lutes is the managing editor and owner at Gun Mann. He is a veteran, gun enthusiast, 3 gun competitor, and 2a advocate. Mike has a passion for innovation and education across the industry to create great content, training, and insights from the best and brightest.

Leave a Comment