Handgun Caliber vs. Stopping Power

Many of your are aware that I write self-defense/Second Amendment articles each month for several widely read publications. So, besides having ridden millions of street miles on two wheels, I am very proficient and knowledgeable about firearms and self-defense. I have trained in self-defense for many years including the following disciplines: Close Quarter Combat (CQB) with firearms and fixed blade knives, batons and Krav Maga. Additionally, I have shot both pistol and rifle competitively for many years. While I am by no means an expert on ballistics and the physiology of a mortal gun shot wound – I am very well read on both.

So yesterday, I posted a poll on Twitter asking everyone what caliber pistol was their favorite. Twitter polling does not allow a lot of choices in their polls, so the options I provided were: .45 ACP, 9mm, .40 S&W and .357 SIG – the latter of which is my favorite caliber. More on this later. But lets look at the poll:

The poll is now closed and the final results are:

  1. 9mm = 54%
  2. .45 ACP = 23.4%
  3. .40 S&W = 13.2%
  4. .357 SIG = 9.4%

These results do not surprise me in any way. 9mm is by far the most popular cartridge in semiautomatic pistols. I am sure .38 Special/.357 magnum would have done well also, but since I no longer carry revolvers, I only included the semi-auto calibers. The .357 SIG cartridge was included because it is my favorite caliber. If I had substituted .380 ACP in its place, I am guessing it may have changed the stacked rankings a bit.

But one comment on my poll caught my attention:

My response is as follows:

Let me just say this. Stopping power is not a myth. There are several things which need to be understood to understand what creates “Stopping Power.”

Key Factors Determining Stopping Power

  1. Caliber
  2. Distance to the bad guy
  3. Kinetic energy of the projectile
  4. Type, size and weight of the projectile/bullet
  5. Placement of the shot

Many of these are interconnected. The size/weight/type of the bullet + the distance to the target determines the kinetic energy the projectile will deliver. The placement of the shot determines the amount of kinetic energy absorbed by the target’s tissue.


Any caliber of gun, from .22 short rifle to a 50 BMG, can dispose of a bad guy. Period. But it is a proven fact that a larger caliber (diameter) projectile will create a larger wound channel.


Distance to the bad guy correlates directly to how much kinetic energy is slammed into the thug’s vital tissue. The closer you are to the bad guy the more damage a well placed shot will do.

Kinetic Energy

The release of kinetic energy into the violent thug is the most important of these five factors and depends wholly on each of these factors. And the kinetic energy directly correlates to the severity of the injury and how quickly the shitbag is incapacitated.

Bullet Weight/Type/Diameter

The weight and size of the bullet is key to determining “stopping power.” The type of bullet: hollow point, frangible, ball/full metal jacket (FMJ) or plated determines how the projectile acts when it hits the target.

Shot Placement

All things considered, shot placement is what will get the job done quickly with any caliber of bullet. If you plunk the thug in the heart or cranium it will take the fight out of them quickly. While you may be able to consistently hit the “10” ring on a paper silhouette or the head on a paper figure, that is not the real world. If you are using a .22 rim-fire out of a short revolver, hitting the head or heart in a scary, confusing, fast moving altercation is not easy. You certainly do not want to rely solely on luck to save your life.

Understanding Kinetic Energy

Kinetic Energy Formula

Any moving object creates kinetic energy. A coin dropped from a 100-story building is going to create kinetic energy as it falls to the ground. It will reach a certain speed in the fall, gain no more, and hit the pavement below. When it hits that pavement it will stop (and probably bounce) – the initial impact will release the majority of the energy of its mass into the pavement. In fact, it will probably crack the cement from that height. Each successive bounce will have significantly less energy than the initial impact – until the coin is at final rest and has no energy.

Now let’s look at a coupe real-world examples of the kinetic energy of my preferred calibers for personal protection. I hand roll all of my defense ammunition using Speer Gold Dot bullets, on shiny new Starline brass with Winchester primers. As I am working up the dopes (recipes) for a given caliber and bullet weight, I will try multiple powders and multiple powder weights. I will then shoot them through my chronograph to get the mean velocity of a batch – which has the best compromise between velocity and accuracy.

Here is an example of my preferred recipe for .45 ACP personal protection ammunition in a full sized 1911:

Caliber.45 ACP
Reload Date16 November 2018
BulletSpeer Gold Dot HP
Bullet Weight230 grains
Powder MfgAlliant
Powder TypePower Pistol
Powder Charge7.1 grains
Primer MfgWinchester
Primer NumberWLP (large)
BrassStartline +P (New)
Cartridge Overall Length (COAL)1.200″
Mean Velocity (as tested)975 FPS
.45 ACP 230 Gr Gold Dot – Preferred Dope (recipe)
Note: This is for reference only – work your own dopes up slowly with a reputable reloading manual

Now, that I know the velocity, at 10 foot (where the chronograph was placed), and the weight of the projectile, I can calculate what the kinetic energy of this ammunition will be at 10 foot distance. I plug it into my custom built calculator and come up with this:

This recipe will create 486 ft/lbs. of energy at 10 feet

Now, here is the same calculation, with my preferred reload recipe for my favorite everyday carry pistol: my SIG Sauer P226 Legion in .357 SIG.

Caliber.357 SIG
Reload Date26 July 2018
BulletSpeer Gold Dot
Bullet Weight125 grains
Powder MfgAlliant
Powder TypePower Pistol
Powder Charge8.3 grains
Primer MfgCCI
Primer Number500 (small)
BrassStarline (New)
Cartridge Overall Length (COAL)1.135″
Mean Velocity (as tested)1,442 FPS
.357 SIG 125 Gr Gold Dot – Preferred Dope (recipe)
Note: This is for reference only – work your own dopes up slowly with a reputable reloading manualx

Once again, I know the average mean velocity of my most accurate recipe at 10 feet. With that, I can plug the numbers into my calculator to get the average kinetic energy of this round at 10 feet:

This recipe will create 577 ft/lbs. of energy at 10 feet

Remember, kinetic energy is the force which a projectile (bullet) will have when it hits the target (person) at a certain distance. How that force reacts – and how much force remains – is dependent on several factors: distance to target (the further away, the less energy), type of bullet used – FMJ, hollow point or frangible – and where your bullet strikes. Obviously, especially with a handgun, where the bullet slows quickly, the potential energy which hits the target will be far less at 30 feet than at three feet. That is just simple physics. I will only say one thing about the bullet type. If you are using anything other than a jacketed hollow point projectile, you are putting your life and innocent people’s lives in danger. And this is why:

  1. FMJ/hardball ammunition was the ammo of choice for years. Whether it be in war, LEO use or personal protection use. But this type of bullet was replaced with a more effective bullet years ago: the jacketed hollow point. The reason that the FMJ has been kicked to the curb by law enforcement is because it does not expand. Without expansion it passes right through the bad guy’s body and perhaps into an innocent bystander standing nearby. And because very little energy is absorbed by the bad guy, unless you hit a major bone group, he is free to keep coming at you until he bleeds out.
  2. A recent craze in personal protection ammunition has been frangible rounds. In theory, the frangible round quickly breaks up into dozens of little metal shards. I know, it sounds very good. Like a shotgun, right? It would be like a shotgun if it had the energy of the shotgun shell. But even if the person is wearing very light clothes, these frangible bullets essentially shatter and become very small pieces. The weight of those pieces determine the kinetic energy of each piece – in other words they lose all of their energy because they weigh next to nothing. They will not pass through a rib or a sternum effectively. If it is winter, and the person has layered their clothing and has on a heavy jacket, this problem will only be amplified.

Each of you can make the decision on what caliber of gun you carry and what type of ammunition you load in it. But, I would highly recommend staying away from every type of cartridge besides the jacketed hollow point. The modern jacketed hollow point is designed to get adequate penetration and unload every bit of its kinetic energy in the thug – while not passing through them – jeopardizing others. That is where “Stopping Power” comes from.

The physiology of a fatal gunshot wound

When a person is shot, it creates tissue damage. Some tissues, like skin and lungs, have low density and high elasticity. Most often, if these are the only tissues damaged, the person will not die as quickly (the caveat being the lungs – more on this later). This low density, high elasticity tissue, reduces the amount of energy the tissue has dumped into it – and the damage done. Muscle has higher density and less elasticity than skin and lungs, so more energy will be released into muscle than into skin and lung tissue. Bone has high density and low elasticity. When a bullet hits a heavy bone mass, it will shatter the bone (if it still has enough kinetic energy) and if it is a jacketed hollow point, it will greatly expand and cause severe tissue damage and bleeding once in the body. Organs like the brain, liver and spleen are severely damaged because they lack elasticity. Fluid filled organs like the heart, large blood vessels, bladder and bowels have higher density because of the fluids, so tremendous amounts of energy will be released into them by the projectile – usually causing them to explode – doing tremendous damage.

What will quickly incapacitate a bad guy – eliminating the threat he posed moments before? First, we must examine the effect a bullet has going into the human body. It creates a wound channel. The smaller the wound channel, the less damage it does (BIGGER is always BETTER). The penetration and quick release of energy creates a shock wave as it penetrates tissue, muscle, bone and organs. This shock wave slams through adjacent tissue, organs and bones causing extensive collateral damage. In the case of a FMJ bullet, the wound channel will be there, but the accompanying release of energy will not be as great, allowing the bullet to completely pass through. The optimum bullet is going to hold together, expand greatly and dump all of its energy in the body cavity. This dump of energy, and the damage it does to tissue surrounding the wound channel, is what causes rapid incapacitation. The shitbag will quickly go into shock and bleed out. And while the first paragraph in this section spoke about the lungs being of low density and high elasticity, today’s modern hollow point ammunition has to go through muscle, and also bone, to get to the lungs. By this time the bullet has fully expanded and is dumping its energy as it enters the lungs. The mushroomed bullet will tear apart the lung tissue with the lungs rapidly filling out with blood. The bad guy is well ventilated and will quickly cease to be a threat.

Because stopping power is a function of the size of the wound channel and the tissue damaged by the resulting shock wave, it would be good to look at the kinetic energy popular calibers create.

Kinetic energy of popular handgun calibers

CaliberKinetic Energy (at muzzle)
.22 Short (29 gr)77 Ft/Lbs
.22 Win Mag (45 gr)112 Ft/Lbs
.25 Automatic (35 gr)74 Ft/Lbs
327 Federal Magnum (100 gr)435 Ft/Lbs
.380 ACP (90 gr)162 Ft/Lbs
9mm Luger (124 gr)262 Ft/Lbs
.357 SIG (125 gr)577 Ft/Lbs
38 Special (110 gr)220 Ft/Lbs
357 Magnum (125 gr)434 Ft/Lbs
.40 S&W (165 gr)396 Ft/Lbs
10mm Automatic (180 gr)590 Ft/Lbs
44 Magnum (240 gr) (long barrel)1,008 Ft/Lbs
.45 ACP (185 gr)371 Ft/Lbs
.45 ACP (230 gr)486 Ft/Lbs
Sample table of Popular Handgun Calibers – Kinetic Energy


Any handgun caliber, from a 22 Short to a 44 Magnum, can be lethal. There is a tradeoff between high kinetic energy smaller caliber round, like 327 Federal Magnum, and a large caliber, high energy round like the 44 Magnum. You need to choose your handgun carefully and make sure you are comfortable shooting it. My recommendation is to shoot the highest energy round, in the largest caliber you can handle. Cartridges like .357 SIG, 357 Magnum, 10mm Automatic and 44 Magnum have significant recoil – and often a large muzzle flash/blast which will make you easy to spot in dim light. My recommendations for average shooters are:


The 9mm used to be much maligned by LEOs and self-defense instructors. Their observations were that it would often take several rounds to incapacitate a criminal and if they were wearing heavy clothing the bullets would not fully penetrate the body cavity. With today’s quality personal protection high-velocity 9mm ammo, the 9mm is a fantastic choice for self-defense and offers great stopping power – all with relatively low recoil.

.40 S&W

In the 1980s, with criminals using body armor, the FBI needed a more powerful cartridge than standard .38 Special and 9mm. After much testing the FBI selected the 10mm – which is also known as 10mm Magnum. But during agent qualifications, they found that many veteran agents could not handle the recoil of the 10mm. Their accuracy with this cartridge – especially on follow up shots – was terrible. So they went to famed shooting instructor Jeff Cooper – who along with Smith & Wesson – created the 10mm short – which was quickly renamed the .40 S&W. It offered significantly more “stopping power” but with noticeably less recoil and muzzle flash. Since its inception it has become widely used by LE – because it offers the best compromise of stopping power and manageable recoil. While this caliber definitely has more recoil than the 9mm – it has close to 70% more energy.

.45 ACP

The .45 Automatic Colt Pistol (ACP) has literally been around for 110 years. It does not offer the velocity of the .40 S&W or 10mm, but it is very easy to shoot and the recoil is very manageable. The fact that it packs over 450 Ft/Lbs of energy with a 230 grain hollow point, and creates a huge wound channel (nearly 1/2 inch entry wound), makes it very lethal. And with that much energy, the shock wave created around that large channel is devastating. This is why this caliber has lasted over 100 years.

This article is designed to be both informative – and entertaining. If you stay with the common handgun calibers, and use quality factory hollow point ammunition, you will have more than enough horsepower to take care of yourself. But you must practice ALL THE TIME! If you cannot hit your target, center-mass, nearly every single time, you either have too much gun or you have not practiced enough.

#2A #MolonLabe #ComeAndTakeThem

The Grey Beard Biker™️
@Biker4Life on Gab

About the author

Living in Tennessee, The Grey Beard Biker™️ has been riding motorcycles for many years. He is the original cigar smoking, bourbon drinking, gun toting patriot. He has traveled the United States on motorcycles and is always seeking out new adventures. Watch for him, and his beautiful Tarheel, Racy, riding around on the Grey Ghost!