Rev GaGG Rants (RGR) – The Myth of Stopping Power

Why Do I Keep Hearing About Stopping Power?

“Does the 9mm have enough stopping power for self-defense?”

“Which caliber has the most stopping power: the 9mm, 40 S&W or the 45 ACP?”

“How much stopping power does the …?”

gun, firearms, shooting, stopping power

Now That’s Stopping Power! (Source:

Every day I am asked or I run across questions about this topic. You see, the rants, tirades and flame wars regarding stopping power are on forum after forum after forum. In the gun community, a lot of time and energy is spent asking, answering and arguing this generic topic – stopping power. What is worse is that very knowledgeable and experienced “gun folks” repeatedly bring up and discuss this concept.

Please Stop (Now That’s Stopping Power!)

I am begging you – STOP!

shooting, gun, firearms, stopping power

Please, Please STOP! (Source:

“Stopping power” when referencing bullets and humans IS NOT, NOR WILL EVER BE measurable.

stopping power, shooting, gun, firearms

Inanimate Object (for reference)

The only context that is measurable with regards to stopping power is relative to inanimate objects where the pure laws of physics apply (e.g., two trains running into each other). Stopping power relative to animate objects is always immeasurable.


A bullet hitting an animate body can have some (note the word some) deterministic effects. It can be expected to expand, but how and how fast it expands can vary based on the tissue type it passes through. It can be expected to penetrate, but the depth of penetration can vary based on the physics of the bullet at impact and (again) tissue type. In the end, to “stop” an animate object depends on more than the bullet and its physics, but equally (maybe more so) on the physiology, shot placement and other factors.

gun, firearm, shooting, stopping power

At One Time an Animate Object (for reference)

WTH Does It Mean?

Even before we begin examining all of that…what the heck does it mean to “stop” an animate object? For inanimate objects it is simple – it ceases its progress. For animate objects, what does it mean?  Does it not move an inch, or a foot or two further (not ever going to happen)?  Does the creature drop dead instantly (rare for this to happen even in highly controlled scenarios)  Does it pick the creature up, throw it 5 feet back and then stomp on it with golf shoes??

Right away, it can be seen that the measurement criteria of “stopping power” has many subjective meanings.

Let’s just push this whole conundrum aside and give it criteria for measurement. Let’s say for animate, living objects that “stopping power” means to immediately anchor (drop in place) and produce imminent death.

OK, Let’s AssUMe

Given this definition, what produces this state most effectively? The prioritized, key elements that would produce this terminal state are:

  1. Biological systems function knowledge – in living creatures, the main way to most effectively create immediate anchoring and imminent death is to cause brain or high-spinal cord damage.
  2. Physiology knowledge – knowing the organs, tissue types and structures around the key locations associated with the proper brain or spinal locations.
  3. Strike placement – it is critical to know whether or not a bullet or hammer is hitting the right spot from the right direction.
  4. Dumb luck – even if you hit exactly as biology and physiology dictate, complete randomness can play a part. For instance, what if the creature has a tumor in the related tissue and the bullet expands too fast? What if the angle of a bone or organ is slightly different?
  5. Wound channel – given biology and physiology are only approximate sciences (in certain degrees), next to come into play are the wound channel dynamics and characteristics.  Larger, longer wound channels are more forgiving to individual variances.
shooting, gun, firearm, stopping power

Shoot Here or Here

Notice that “caliber” was not even mentioned in the top 5 key elements to produce an objective stopping power semantic.


Well, let’s be clear… My statement of “caliber was not even mentioned” is to some degree true. In speaking of the wound channel, a vague notion of caliber is present. More specifically, we know that a 9mm or 45 ACP will generally produce more “wound channel” than a .22. That said, given elements 1-4, a .22 can produce the objective definition of stopping power.

The point here?  Caliber is a minority element of any possible definition of animate object stopping power, thus making it largely irrelevant.

For an artificially defined stopping power, we see that placement, luck and decent wound channel characteristics are the major elements.

But isn’t wound channel related to caliber? Yes and no. Modern ballistics and bullet technology have closed many of those gaps. Yes, in the golden years of guns (aka the past and simple ball or lead ammunition), a 45 ACP had a vast difference in wound channel characteristics over a 9mm (or 38). Oftentimes the difference was 50%-100% or more, while today it is 20% or less. In many cases, I can find a bullet in any 38/9/40/45 that will reasonably perform the same as the others.

wound channel, firearms, shooting, stopping power

Now That’s a Wound Channel! (Source:

Contrived Misbeliefs

All of this is based on a contrived and artificial definition of animate (living) object stopping power because:

  • it is a 1 placement scenario (brain pan or C4/5)
  • it assumes this scenario always produces the same result
  • it fails to account for endocrinology – or better known as adrenaline

I have spent over 20 years in the trauma medical field. I have worked extensively in ERs, in field trauma and other trauma scenarios. As a police officer, I have seen my fair share of catastrophic injuries. Here is a little secret:

Homie don’t play that…

In other words, humans are indeterminate creatures. I have witnessed people walk away after sustaining severe head and neck wounds that were sufficient enough to have caused death. I have seen people go into comas who experienced only minor injuries. Every human responds totally different.

shooting, firearms, stopping power

Harpoon to the Brain Pan – Man Lives (Source:

Granted, the artificial scenario we stated would (in most cases) produce a stopping power scenario.  But,  X-rays exist where there are those who still have bullets in their heads from being shot straight into their brains. Should a bullet deviate a little right/left (due to skull density)…voila, a walking bullet carrier!

Join Me

So, join me in a cause… A cause to end all causes… Let’s stop this myth of stopping power, here and now!

Calibers can have effects.

Bullets can produce wound channels.

Bullet placement can have the probability of wounding or lethality.

But, no bullet shot at an animal or human has any measurable “stopping power”.

It’s a myth!

Mic drop! Rev GaGG out of here!

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