The debate over which pistol caliber is best for self-defense has been raging for decades. Gun owners are typically passionate about their choices and the argument often turns ugly.
This article probably won’t put a stop to the “best caliber for self-defense” bickering. However, by looking at the stats and data for the most popular defensive cartridges in current production, we can help you make an informed decision about what will work best for you.
This article will also offer some sound science you can use when you find yourself embroiled in a hot dispute over your favorite self-defense cartridge.
Choosing the Best Caliber for Self-Defense
Deciding on a self-defense cartridge is a highly personal decision. There is no perfect one-size-fits-all best self-defense caliber. What works well for one shooter might be an absolute nightmare for another.
To gain advantages in one area (like terminal energy), you’re going to need to make concessions in others (like recoil energy). Finding the right cartridge for defensive needs is all about finding a balance between what you can shoot, what you can comfortably carry, and what has enough power to make short order of a dangerous threat.
Here is a list of the most popular options modern shooters use for defensive carry. Each has its pros and cons.
Looking at the data and using our personal experiences, we’re convinced that the 9mm Luger is the best all-around handgun cartridge for self-defense.
However, smaller shooters often find 9mm pistols difficult to shoot and even harder to conceal. We’ve chosen the 9mm because it works well for the vast majority of shooters in most defensive applications.
9mm Luger – Our Top Pick
9mm Luger (also called 9×19 Parabellum or simply 9mm) was once considered a subpar option for personal defense. Times have changed. Today, the 9mm is the most popular cartridge for both law enforcement and civilian concealed carry, and it earned that popularity fair and square.
Recoil
As Sir Isaac Newton so eloquently put it in his Third Law of Motion, “For every action, there is an equal and opposite reaction.”
In the world of shooting, the opposite reaction to firing a projectile is recoil. Recoil is the amount of “kick” a firearm produces when a bullet is fired. Guns that produce less recoil are generally easier to shoot.
Firearms with extreme recoil can be brutal to shoot, which causes issues with accuracy, especially on follow-up shots.
Compared to larger caliber defense rounds, the 9mm produces relatively mild recoil. Because the 9mm’s recoil is easier to tame, shooters can make faster, more accurate follow-up shots. Since your life depends on good shot placement in a defensive shooting scenario, this is a major selling point for 9mm.
The subject of recoil isn’t always cut and dry. For example, a micro 9mm will be tougher to control than a full-size .45 ACP.
Power and Penetration
When it comes to “stopping power,” 9mm is very ammo specific. Modern advancements in ammo technology have brought the terminal performance of the 9mm up to par with much larger caliber cartridges. Today’s 9mm ammo shoots faster, hits harder, and expands larger than the 9mm ammo we were shooting just a decade ago.
However, when it comes to personal protection, some 9mm loads work better than others. For best results, choose expanding hollow points for your self-defense handgun.
Capacity
Although actual capacity varies by model, 9mm offers greater capacity than most other popular concealed carry calibers. Because 9mm cartridges are smaller than .40 S&W or .45 ACP, they don’t take up as much space in a magazine, which allows for greater round capacity.
Cost and Availability
9mm Luger ammo is pretty affordable compared to other popular pistol calibers. That means you won’t need to drop a ton of cash on your carry ammo.
Because practice loads are relatively cheap, you can hone your skills without hurting your bank account. Since weapon proficiency is a necessary component of defensive shooting, this is another major perk for 9mm.
The 9mm Luger is one of the most popular cartridges on the market today. There is no shortage of 9mm pistols or ammo to choose from. Every major manufacturer offers multiple gun models, with everything from autoloaders to revolvers, subcompact to full size. There are also hundreds of defense-specific loads for shooters to choose from.
.380 ACP
The .380 Automatic Colt Pistol (also called .380 Auto and .380 ACP) was introduced in 1908. It was designed for the blowback pistols of the time. Compared to more modern pistol cartridges, the .380 ACP lacks the power, speed, and terminal performance to make it a serious option for personal protection or home defense.
So why is it included on this list?
When you need it, even a small gun like the .380 ACP is better than no gun at all.
We believe the .380 Auto works best as a backup gun rather than a primary concealed carry weapon. Their ultra-compact size and easy concealability make them perfect for that role.
Get a quality pocket or ankle holster, and a.380 ACP makes a great sidekick for your EDC sidearm.
Recoil
Although .380 ACP and 9mm Luger use the same diameter projectiles, .380 pushes lighter bullets at slower speeds. While the .380 ACP may be lacking in velocity, those slower speeds mean less recoil energy.
Recoil is affected by a ton of variables. One of the most significant is gun weight. Heavier guns soak up more recoil than lighter ones. Although the .380 ACP produces less recoil energy than any of the other cartridges on this list, these cartridges run through tiny, lightweight pistols. Lightweight pistols don’t absorb much recoil energy, so most of it transfers to the shooter.
When shooting the tiniest .380 Auto micro pistols, you might feel more recoil than when you’re shooting a compact 9mm. For example, a 95-grain projectile leaving the muzzle of a .6-pound .380 Auto pistol at 900 fps generates 5.4 foot-pounds of recoil energy. A 115-grain bullet traveling 1150 fps from the barrel of a pound-and-a-half 9mm produces 5.2 foot-pounds of recoil. Not much difference.
Add a little more heft to the gun and the 9mm gets even easier to shoot. When shot from a two-pound pistol, that same 9mm bullet only kicks 3.8 foot pounds. That’s significantly less recoil than the .380.
Power and Penetration
The .380 Auto and the 9mm Luger use the same size projectiles. However, the .380 ACP cartridge has an overall length of .984 inches and a SAAMI maximum pressure of 21,500 psi. In comparison, the 9mm measures 1.169 inches and has a maximum pressure of 35,000 psi.
Because both cartridges use the same diameter bullets, depth is the main difference in the wound channels they produce.
The Federal Bureau of Investigation uses specific penetration test protocols to determine the effectiveness of defensive loads. According to FBI performance standards, a bullet should penetrate at least 12 inches into ballistics gel, but no more than 18 inches.
Meeting those protocols is difficult for .380 ACP with expanding bullets because a good portion of the penetrating energy is used up during expansion. Penetration can be much shallower if those bullets pass through heavy clothing first.
While non-expanding FMJs have an easier time reaching the magic 12-inch depth, the wounds they carve are not as wide. Since fractions of an inch matter when it comes to organ and artery damage, using a non-expanding bullet sacrifices terminal damage. Simply put: bigger holes stop assailants faster than small ones.
Capacity
Tiny backup pistols don’t need to carry a bunch of ammo. The Glock subcompact G42, which is chambered in .380 Auto, has a standard magazine capacity of only six rounds.
Although you can purchase, 15-round magazines, it makes the pistols much more difficult to conceal.
Cost and Availability
Micro pistols designed for James Bond-style deep concealment are all the rage right now. That means there is a wide variety of .380 ACP pistols on the market.
Unfortunately, there isn’t nearly as much variety in the ammo department. Although most major manufacturers have several .380 ACP loads in their line-ups, there isn’t nearly the selection that you’ll find for more popular loads like 9mm or .45 ACP.
The ammo you do find will also cost you. Most .380 ACP loads are significantly more expensive than 9mm. Cost-wise, they are more on par with hefty hitters like .45 ACP.
.38 Special
If you’re a fan of wheel guns for self-defense, the .38 Smith & Wesson Special (more commonly known as simply .38 Special) is a popular option. A revolver chambered in this mild-recoiling cartridge is capable of stopping bad guys. However, it does have its drawbacks.
Recoil
The .38 Special’s recoil is incredibly mild, which is why this cartridge is often recommended to women and other recoil-sensitive shooters.
Load a snub nose revolver with .38 Special and the recoil gets a bit snappy. Although snubbies are easier to conceal, a medium-frame wheel gun is much easier to shoot.
Power and Penetration
Although both 9mm and .38 Special shoot the same caliber bullets, the .38 Special is a low-velocity cartridge, and as such it has a lot less oomph behind its projectiles.
The 9mm Luger has a smaller case capacity (23.4 grains compared to the 9mm’s 13.3 grains). However, the .38 Special’s case was originally designed to house black powder, which produces lower pressures than modern smokeless powder. and was therefore engineered to handle those lower black powder-level pressures.
To put the power difference in perspective, .38 Special cartridges have a SAAMI pressure specification of 17,000 psi. If you can get your hands on .38 SPL +P loads, those top out at 18,500 psi. In comparison, 9mm (which is quickly becoming the gold standard for self-defense ammo), has a SAAMI rating of 35,000 psi.
A standard pressure .38 Special loads launching a 125-grain bullet at 900 fps generates 225 foot-pounds of energy. Meanwhile, a standard pressure 9mm load lobbing a nearly identical projectile achieves a velocity of 1175 fps and 380 foot-pounds of energy.
While that is a significant difference of force in the 9mm’s favor, modern bullet designs have helped even the playing field for these two cartridges.
The .38 Special performs well in FBI penetration protocol tests. Although it doesn’t penetrate as deeply in ballistics gel as 9mm, that isn’t always a bad thing. Even when loaded with FMJs, .38 Special rarely over penetrates except at the closest defensive distances.
In crowded areas or scenarios where your family is sleeping somewhere behind the bad guy, a bullet that expands in soft tissue and then stays there is a good thing.
Capacity
Most revolvers chambered in .38 special only hold 5 to 6 rounds, and wheel guns aren’t exactly easy to reload.
While 6 rounds of .45 ACP might be enough to stop someone hellbent on violence, that many rounds could still be a stretch for .38 Special to achieve the same thing. Smaller caliber projectiles create smaller wound channels, so round count becomes that much more important.
Cost and Availability
Because Americans have a love affair with semi-automatic polymer pistols like Glocks, SIGs, and Smith & Wesson M&Ps, plenty of them are designed and manufactured each year.
Unfortunately, that means fewer revolvers are hitting gun stores except as second-hand purchase options. Even fewer revolvers chambered in .38 Special are rolling off assembly lines these days, so your options for a carry gun chambered in this mild-recoiling cartridge may be few and far between.
Even in the world of firearms, demand affects supply, and as fewer wheel guns chambered in .38 Special hit the market, ammo options also decline.
Even cheap .38 Special ammo tends to run on the expensive side, especially compared to more popular options like 9mm. However, .38 Special is still more affordable than .45 ACP.
If you want to save money, buy your practice ammo in bulk.
.357 Magnum
The .357 Magnum was easily the most popular handgun cartridge of the twentieth century. Introduced in the 1930s, the .357 Mag was designed as a high-velocity round to help law enforcement punch through car doors and auto glass used as cover by Prohibition-era gangsters.
Although modern shooters have embraced newer cartridges designed for semi-automatic pistols, the .357 Magnum still has plenty to offer defensive shooters.
While .357 Magnum revolvers are generally too bulky and heavy for concealed carry, they make great sidearms.
Recoil
It’s safe to expect any cartridge with the word “Magnum” in its name to be a heavy kicker. However, on the spectrum of handgun recoil, the .357 Magnum sits somewhere in the middle.
The average recoil produced by a .357 Mag wheel gun will be slightly heavier than the average 9mm. However, the kick is significantly milder than the recoil generated by .40 S&W.
Power and Penetration
the .357 Magnum has more velocity and delivers more energy both at the muzzle and on downrange targets than the 9mm standard.
The .357 Magnum is packed with a slightly beefier bullet than the 9mm (0.357 inches for the Magnum vs. .355 inches for the Luger). A larger diameter bullet hitting with more force leads to more tissue damage, blood loss, and pain, all of which are necessary for quickly and effectively eliminating a threat.
Capacity
Because the .357 Mag is typically loaded into revolvers, shooters are usually limited to five or six shots.
Cost and Availability
Most new .357 Magnum handguns can also safely run .38 special cartridges, which adds to their versatility. However, the selection of guns chambered for this magnum cartridge is generally limited to revolvers.
When it comes to price, both .357 Mag practice and defensive ammo cost significantly more than 9mm. However, there are plenty of different load options available to modern shooters, and you can always save a few bucks by buying in bulk.
.40 Smith & Wesson
Sitting squarely between the popular 9mm and .45 ACP, the .40 Smith & Wesson (.40 S&W or simply .40 for short) is often called the “compromise cartridge.”
Introduced in 1990, the .40 S&W is a relative newcomer. The cartridge was specifically developed to match the performance of the FBI’s reduced-velocity 10mm Auto. Designers reduced the 10mm’s powder charge, removed the extra empty space, and shortened the case length to produce the new .40 S&W.
Recoil
The .40 S&W has a reputation for having snappy recoil and significant muzzle rise, both of which can be difficult for inexperienced shooters to tame.
Because the .40 S&W shoots a smaller projectile, it is easy to believe it should have less recoil than the larger .45 ACP. However, the numbers tell a different story.
A 155-grain bullet shot from the muzzle of a 1 ½-pound .40 S&W pistol kicks with 10.6 foot-pounds of recoil energy. In comparison, a 2 ½-pound .45 ACP pistol throwing a 185-grain projectile only produces 6.8 foot-pounds of recoil.
The heavier weight of the .45 ACP certainly helps mitigate some of the recoil force. However, many shooters claim the .40 S&W’s recoil is harsh, snappy, and more difficult to control. The numbers certainly support that claim.
Power and Penetration
The .40 S&W shoots the same projectiles as the 10mm Auto. Because the .40 S&W’s case holds 4.8 grains less powder than the 10mm, the cartridge shoots projectiles at slower speeds with less energy.
The faster, beefier 10mm sends 175-grain pills downrange at 1160 fps with 523 foot-pounds of muzzle energy. The .40 S&W shoots the same projectiles 150 fps slower with only 396 foot-pounds of energy.
When we compare the power of the .40 S&W to our favorite 9mm, the drift and drop are pretty comparable. However, the .40 has a clear energy advantage. The 9mm’s lighter projectiles leave the muzzle carrying only 339 foot-pounds of energy.
Even the terminal expansion between the two calibers isn’t all that different.
9mm loads designed for massive expansion open up to 0.72 inches.
Mushrooming .40 S&W loads expand to 0.76 inches.
The expansion similarities mean the width of wound channels for the two is pretty similar. However, with the extra energy pushing the .40 S&W, not only does it drive deeper, but it also transfers some serious concussive energy to a soft tissue target.
Capacity
While most .40 S&W handguns have capacities comparable to 9mm models, the .40 S&W models are typically heavier, bulkier, and more difficult to conceal.
Cost and Availability
In the not-so-distant past, the .40 S&W was incredibly popular with both law enforcement and civilian shooters. However, as the 9mm’s popularity has surged, the .40’s has waned. As a result, both handgun and ammo options are dwindling.
10mm Auto
First introduced in 1983, the 10mm Auto (also affectionately dubbed the “Bren Ten”) earned a ringing endorsement from defensive shooting guru, Colonel Jeff Cooper. This powerful round was also favored by large government agencies, like the FBI.
Following the disastrous Miami Dade shootout in 1986 that left two FBI agents dead and another five injured, the cartridge fell out of favor. Eventually, the .40 Smith & Wesson took over the 10mm Auto’s position as the FBI’s official duty round.
Although the 10mm almost fell into obsolescence, modern shooters are falling in love with this cartridge all over again.
The 10mm makes a powerful defensive load and is also popular for handgun hunters. If you live in an area where defensive shooting involves critters as much as dangerous humans, this cartridge deserves some serious consideration.
Recoil
The main reason the FBI abandoned the 10mm Auto is that many of their agents were overpowered by its hard-hitting recoil. It was particularly difficult for them to make fast, accurate follow-up shots, a crucial skill in their line of work.
A 180-grain projectile fired from a 2.25-pound 10mm pistol kicks the shooter’s hand with 11.4 foot-pounds of recoil energy. That makes the recoil significantly punchier than the other cartridges on our list, even heftier than most .44 Magnum loads.
The recoil of the 10mm definitely isn’t for the faint of heart. It certainly doesn’t make for a fun day of high-volume target shooting. Since it takes practice to develop proficiency, this is a major drawback for most shooters.
Power and Penetration
No one is going to argue that 10mm Auto is an absolute powerhouse. Critics often call it too powerful for self-defense.
The 10mm Auto sends a 175-grain projectile downrange at 1160 fps with 523 foot-pounds of energy.
It holds onto that energy fairly well. It’s still toting 437 foot-pounds at 50 yards. That means this cartridge is a handy one for stretching beyond typical defensive shooting distances.
Because of all that energy, the 10mm Auto often gets a bad rap for over penetration, which can be a serious problem in crowded situations. However, the over-penetration issue can be solved by choosing loads designed for massive expansion, like Federal Personal Defense HST or Hornady Critical Duty.
Capacity
Standard size 10mm pistols generally have mag capacities on par with a standard size 9mm or .40 S&W. A standard 10mm pistol will be slightly larger and heavier than a standard .40 S&W, but significantly bulkier than a standard 9mm.
The size and weight of 10mm pistols make them difficult to conceal. Subcompact models are much easier to conceal and more comfortable to carry. However, smaller 10mm pistols are significantly more difficult to shoot.
Cost and Availability
Because the 10mm Auto doesn’t enjoy the popularity it did in days gone by, there are fewer gun and ammo options available than there used to be. However, the 10mm is regaining much of its former popularity. If it continues on this trend, we should see more pistol and ammo offerings from manufacturers in the near future.
During the COVID-19 pandemic ammo panic, where you couldn’t sniff out a 9mm or .45 ACP round with a bloodhound, most shooters could still get their hands on 10mm Auto. If you want a panic-proof cartridge, 10mm Auto should probably be your go-to.
.44 Remington Magnum
The .44 Remington Magnum (also known as .44 Magnum or 10.9x33mmR) is definitely the most powerful cartridge on this list. The cartridge is almost synonymous with Dirty Harry’s double-action Smith & Wesson Model 29 revolver, which was labeled by the manufacturer as “the most powerful handgun in the world.”
Since the .44 Magnum’s release, other more powerful cartridges have been developed. However, the .44 Magnum is still a heavy-duty, hard-hitting cartridge.
Recoil
This is a magnum cartridge, magnum cartridges produce serious energy. With serious energy comes serious recoil.
Even strong, experienced shooters can have a hard time controlling the recoil from a .44 Magnum.
Power and Penetration
The .44 Magnum produces muzzle velocities around 1500 fps with hard-hitting muzzle energy near 1000 foot-pounds. That energy is one reason this cartridge is preferred by handgun hunters pursuing big game.
All that power makes over penetration a serious concern when using .44 Magnum for personal protection. However, if you live in bear country, your home defense weapon needs to have enough power to stop an angry bruin. In that case, that power becomes a major perk rather than a hindrance.
Capacity
Most .44 Magnum revolvers hold either five or six rounds.
Cost and Availability
Expect to invest some cash in a .44-caliber firearm. Although big bore revolvers are the most common .44 Magnum guns on the market, you can also find lever-action carbines chambered for this cartridge.
.45 ACP
The .45 Automatic Colt Pistol (also known as .45 ACP or .45 Auto) has enjoyed constant fame since John Moses Browning introduced his now iconic 1911 semi-auto pistol, which was originally chambered for this cartridge.
The .45 ACP genuinely speaks to the “bigger is better” personal and home defense crowd.
The cartridge (and the 1911 pistol) are battle-tested options that helped America win two world wars. Not only is this cartridge highly effective, but it is also one of the most reliable options on the market.
Recoil
The .45 Automatic Colt Pistol is a powerful cartridge. While that is good news for defensive carriers, that power and performance come at a price. These auto-loading pistols produce significantly more recoil than 9mm pistols.
Power and Penetration
The 9mm Luger’s power and performance have improved by leaps and bounds over the past several decades. Modern technology has helped the 9mm bridge the gap between it and the .45 ACP. That doesn’t mean .45 ACP doesn’t still have advantages over the Luger.
The 9mm has improved in speed and power. However, there is one area where 9mm will never be able to catch .45 Auto, and that’s expansion.
Larger wounds cause more pain, tissue trauma, and blood loss than smaller wounds. Right out of the barrel, the .45 ACP has almost a tenth of an inch more in diameter than the 9mm. If you’re shooting expanding hollow points, those .45-caliber projectiles can expand up to double their original diameter. That’s a lot of tissue trauma.
If we look at velocity, .45 Auto lobs its bullets at relatively slow speeds. However, that isn’t necessarily a bad thing. Because this cartridge is naturally subsonic, when you pair it with a suppressor, the decibels are reduced to near whisper levels.
If you have to fire your home defense weapon within the tight confines of your front hallway, your ears will thank you for shooting a suppressed 1911.
The .45 also has shallower penetration than most 9mm defense loads. Its slow-moving, bulky bullets often prevent pass-through shots, which is important if you need to shoot a bad guy near innocent bystanders.
Capacity
Although capacity varies by model, the average magazine capacity for sub-compact firearms chambered in .45 ACP is only ten rounds. However, many companies offer extended magazines to increase overall mag capacity, which can be a serious advantage in a gunfight.
Cost and Availability
Gun owners still enjoy a wide variety of .45 ACP ammo, as well as self-defense handguns chambered for this popular cartridge.
Buying .45 ACP ammo is going to cost more than purchasing 9mm rounds, up to twice as much per round in some cases.
Final Thoughts
The 9mm Luger loaded with hollow point projectiles offers a great balance of power, penetration, capacity, and concealability in an easy-to-shoot package.
While the .45 ACP fan club will probably send hate mail, we have to name the 9mm Luger the best caliber for self-defense available to modern shooters. There’s a reason both local and federal law enforcement agencies are returning to 9mm duty weapons.
By Alice Jones Webb Original here.
