What is the Best Self Defense Caliber?

What is the Best Self Defense Caliber? - Uppercut Tactical

According to a 2017 Pew Research survey, self-defense is the most common reason Americans cite to own a gun. Consequently, it is natural for questions such as, “What is the best self-defense caliber?” to be asked frequently by gun owners of all backgrounds and skill levels.

However, while the question may seem simple, the answer is complex. Self-defense is a broad subject encompassing different tasks and scenarios. Understanding the types of self-defense and what makes a particular caliber effective in each situation is crucial for making the best choice.

Types of Self-Defense Scenarios

When asking about the best calibers for self-defense, defining what type of self-defense scenario you intend to prepare for is crucial. Each scenario has different caliber effectiveness requirements, legal considerations, and situational parameters.

Self-defense scenarios fall into four categories: concealed carrying, home defense, open carrying, and SHTF situations. Each has different threat profiles, requirements, and suitable firearms and calibers.

Concealed Carrying

Carrying a concealed weapon is one of the most common ways an individual can prepare for a self-defense scenario outside the home. While concealed carrying is legal in all 50 states with or without a permit, every state has different laws, rules, and requirements.

Concealing a firearm on your person generally involves carrying a handgun, such as a pistol or a revolver, in a dedicated carry holster and under appropriate cover garments. Concealment has two advantages: it allows you to maintain the element of surprise and avoids potential unwanted attention that being visibly armed might bring.

In addition to choosing a suitable self-defense caliber, a well-prepared concealed carrier should also select premium-quality ammunition with projectiles designed for personal defense. Common examples today include jacketed hollow-point bullets (JHP) and ballistic tip projectiles, which are JHPs with polymer inserts. These projectiles are designed to expand into soft tissue, increasing their incapacitating power and reducing the risk of overpenetration.

Although it is possible to conceal-carry a long gun, such as a rifle or a shotgun, with a backpack or another carry bag, it generally falls outside most concealed carry plans due to legal or practical issues. 

Home Defense

Preparing for home defense scenarios requires a plan to protect yourself and your household against potential intruders, such as burglars and other home invaders.

Most homes and apartments fall into the general category of close-quarters environments. Suitable firearms are typically close-range weapons, like handguns and shotguns. However, you may prefer longer-range weapons, such as rifles, if you live in a large home or on a property with lots of acreage, like a ranch or a farm.

Open Carrying

Some jurisdictions allow American citizens to carry a firearm openly, trading the element of surprise for an element of deterrence. Open carrying also expands the range of practical firearm options, potentially increasing the firepower at your disposal. 

For instance, open carry makes it more viable to select a full-sized handgun instead of a compact or subcompact model optimized for concealed carry. Open carrying also enables legally carrying the long guns you might otherwise reserve for home defense, such as rifles and shotguns.

SHTF Situations

SHTF typically refers to extreme and catastrophic events. An SHTF situation is an event that severely disturbs society and regular life, typically to the point of rendering public amenities and services unavailable, such as water, power, police, fire departments, EMTs, banking, or the Internet. 

Common examples of SHTF scenarios include:

  • Natural disasters, such as hurricanes, wildfires, droughts, earthquakes, or tornadoes
  • Failures of critical infrastructure, such as disruption of supply chains, food shortages, or long-term power grid outages
  • Events causing general economic collapses, such as hyperinflation, stock market crashes, banking system failures, recessions, and other long-term economic crises
  • Geopolitical crises, such as civil unrest, riots, large-scale social upheaval, or war and armed conflicts, up to and including nuclear war

While self-defense in SHTF situations can involve principles found in all three other scenario types, they distinguish themselves by the high probability of the rule of law collapsing.

Laws may become unenforceable, and government, law enforcement, and judicial systems are typically compromised or non-functional, creating a high risk for crime, violence, and vigilantism. Ecosystems may also be disturbed, potentially resulting in more wildlife encounters.

Your SHTF calibers and firearms depend on the threats you will most likely face. Another factor to consider is whether you remain in one location or on the move. How you choose to survive an SHTF scenario can change your threat profile and access to suitable firearms.

What is the Best Handgun Caliber for Self-Defense?

Handguns are among the most common firearms used for personal defense. According to a 2021 national firearms survey, handguns are used in 65.9% of defensive incidents. Approximately one-quarter of the incidents occurred within the gun owner’s home, half outside their home but on their property, one out of ten in public, and one-third in the workplace. 

These statistics show handguns may be among the most versatile self-defense firearms available because they have been successfully used for home defense, concealed carry, and open carry.

If you are looking for a handgun for self-defense, select a suitable caliber before choosing a specific gun. Below are some of the most popular handgun cartridges in the United States, their characteristics, and their pros and cons. The comparisons can help you determine what caliber for pistols is the best for self-defense.

9x19mm Parabellum (9mm Luger)

Also known as 9mm Luger or simply 9mm, the 9x19mm Parabellum cartridge is the world’s most widely used centerfire pistol cartridge and one of the best options for self-defense.

The 9x19mm cartridge was initially developed at the turn of the 20th century for the Luger P08 pistol. Numerous iconic handguns are 9mm pistols, such as the Walther P38, the Browning Hi-Power, the “Red 9” version of the Mauser C96, the CZ-75, the Beretta 92, the Glock 17, some variants of the 1911 pistol, the SIG Sauer P226, the H&K USP, and the SIG Sauer M17.

In the past, the 9x19mm cartridge was considered underpowered compared to American mainstays such as .45 ACP or .357 Magnum. However, the popularity of 9x19mm ammunition for self-defense increased as firearms technology progressed.

This caliber now has decades of proven track record for civilian, military, and law enforcement applications. Today’s self-defense 9x19mm JHP loads are highly reliable and effective at stopping threats. Many gun owners consider 9mm the best pistol caliber for self-defense due to its many advantages and few disadvantages.

If this is the choice for you, check out our article on the best 9mm ammo for self defense.


  • High gun capacity: Most self-defense handguns in 9x19mm have a higher capacity than their equivalents chambered in other calibers, such as .40 S&W or .45 ACP. Modern compact and subcompact pistols feature standard magazine capacities of 10 rounds or more, and full-size models can carry 15 to 21 rounds in standard magazines.
  • Recoil: 9x19mm ammunition generates moderate recoil, meaning it is generally easier to shoot 9mm handguns than .40, .45, or 10mm models.
  • Ammo costs: 9x19mm ammunition is typically plentiful and relatively inexpensive, typically hovering around $0.20 per round.
  • Proven effectiveness: 9mm bullets have a nominal diameter of 0.355”, meaning they are smaller than .40 S&W (0.400”) or .45 ACP (0.452”). Despite that, modern 9mm hollow points expand reliably and have a proven track record.


  • Limited case capacity: 9x19mm cases cannot hold as much powder as large semi-automatic calibers like .40 S&W or .45 ACP or magnum revolver rounds like .357 Magnum. This factor inherently limits the maximum bullet weights and velocities a 9mm bullet can reach, making it unsuited for other defensive applications, such as protection against wildlife.
  • Limited expansion: Defensive 9mm ammunition may not expand to diameters as large as defensive bullets in larger calibers, such as .40 S&W or .45 ACP.

.40 S&W

.40 Smith & Wesson (.40 S&W) was introduced to the market in 1990. The first pistol chambered for the new .40 caliber was the Smith & Wesson Model 4006. 

Its parent cartridge, 10mm Auto, was developed in response to the lack of effectiveness of 9x19mm and .45 ACP after the 1986 FBI Miami Shootout. However, following a few years of use by the FBI, 10mm Auto was deemed too powerful and hard to control for the average FBI agent.

A reduced-power version of the cartridge known as the “FBI load” was eventually developed. S&W engineers determined that the FBI load’s performance could be achieved in a shorter case, creating the .40 S&W cartridge: a shorter, more space-efficient version of 10mm Auto.

After its introduction, law enforcement agencies in the United States have widely adopted .40 S&W in pistols such as the Glock 22, where it gained decades of proven effectiveness. Despite a recent resurgence of 9x19mm in law enforcement, “40 cal”  pistols are widely used by numerous local, state, and federal agencies nationwide.

It is also a popular choice for civilian self-defense, with many effective self-defense loads available on the market.


  • Proven effectiveness: Self-defense and police duty JHP ammunition in .40 S&W have decades of proven street effectiveness and reliability. Examples include Speer Gold Dot, Federal Premium, and Winchester Ranger.
  • Gun costs: As law enforcement agencies are switching back to 9mm, the average price of .40 S&W guns is currently low due to the large number of inexpensive police trade-in pistols on the market.
  • Wide expansion: With a starting diameter of 0.400”, self-defense bullets in this caliber can expand to large diameters, translating into a higher stopping power than narrower calibers.


  • Ammo costs: .40 S&W has historically been more expensive than 9x19mm ammunition, making it impractical for practice.
  • Recoil: Ammunition in .40 S&W, especially self-defense ammo, generates more recoil than 9x19mm or .45 ACP. It is considered one of the more challenging handgun cartridges to shoot accurately. 
45 ACP Semi Automatic Pistol

.45 ACP

The .45 ACP cartridge is one of the quintessential American handgun cartridges, designed by legendary American gunsmith John Moses Browning. It was the U.S. military’s service pistol cartridge from 1911 to 1985 and is traditionally associated with the 1911 pistol platform.

Besides the 1911, numerous tactical pistols have been chambered in .45 ACP, such as the Glock 21, the H&K USP and Mark 23, the SIG Sauer P220, the FN Herstal FNP and FNX, the Springfield XDM, or the Smith & Wesson M&P.

Even after the U.S. military transitioned away from the 1911, .45 ACP remains in use among various SOCOM units. Standard-pressure versions propel the .45-caliber bullet at subsonic velocities, making it naturally suited for use with suppressed weapons.

Despite its age, .45 ACP is still considered a highly effective cartridge for self-defense, primarily due to its large-diameter bullet and the availability of various loads.


  • High load variety: .45 ACP is available in standard and high-pressure variants, each with various projectile types suitable for self-defense.
  • Controllable: While .45 ACP has large and heavy bullets, they travel at relatively slow velocities. The felt recoil is frequently described as a “push” instead of a “snap,” particularly out of heavier, full-size pistols. This phenomenon indicates .45 ACP offers a good compromise of controllability and effectiveness.
  • Maximum expansion: As the adage goes, 9mm may expand, but .45 doesn’t shrink. .45 ACP bullets start with a nominal diameter of 0.452”, and expanded hollow-point bullets can reach diameters of 0.900” or wider, showcasing their high stopping power.


  • Ammo costs: .45 ACP is among the most expensive common-use self-defense cartridges, with average pricing typically higher than 9mm and .40 S&W.
  • Low capacity: The large diameter of a .45 ACP cartridge limits the maximum capacity of handguns chambered in this caliber. Typical magazine capacities range from 7 to 15 in full-size pistols. Compacts and subcompacts rarely exceed 10 rounds and may have magazines as small as 6 rounds. 
357 Magnum Revolver

.357 Magnum

The .357 Magnum cartridge is the first and the most common of the magnum family of revolver cartridges. It was created by handgun experts Elmer Keith, Philip Sharpe, and Douglas B. Wesson to increase the effectiveness of the older .38 Special cartridge.

The .357 Magnum case is effectively an elongated version of the older .38 Special, allowing it to store more gunpowder. These cartridges can generate much higher velocities and energy, making the .357 Magnum effective for a wide range of applications.

Although .357 Magnum is primarily known for being revolver ammunition, many rifles, such as the Marlin Model 1894 or the Henry Big Boy, are available in .357 as well. 


  • Highly versatile: With the right velocity and projectile, .357 Magnum is suitable for any application: target shooting, hunting, personal defense, wildlife protection, and more.
  • Compatibility with .38 Special: Virtually all .357 Magnum revolvers and many rifles will also accept the shorter, less powerful 38 Special cartridges, allowing you to practice with more inexpensive ammunition.
  • Powerful and effective: .357 Magnum is considered one of the best revolver calibers for self-defense due to its high muzzle energy and terminal effectiveness. .357 Magnum carries a high potential for one-shot stops during self-defense encounters.


  • Sensitive to barrel length: While short-barreled snub-nose revolvers suitable for concealed carrying are available in .357 Magnum, the cartridge’s performance suffers when fired through short barrels.
  • Recoil: .357 Magnum is a powerful cartridge generating large amounts of recoil. Shooting this caliber quickly and accurately is challenging, requiring steady and constant practice.
  • Capacity: Virtually every .357 Magnum handgun is a revolver, limiting the maximum capacity to 5 or 6 rounds, with a few models carrying 7 or 8.

.380 ACP

The .380 ACP cartridge is another invention of John Moses Browning, who introduced it in 1908 as a more powerful alternative to the earlier .25 ACP and .32 ACP. Unlike the .45 ACP destined for military applications, the .380 cartridge was primarily designed for civilian self-defense from the start.

The first .380 ACP was the Colt Model 1908 pocket hammerless pistol, a handgun destined for the civilian self-defense market. It was considered moderately powerful throughout the first half of the 20th century, leading to numerous European military and law enforcement agencies pressing it into service. 

In the United States, the .380 ACP has been primarily viewed as a caliber for police backup guns and civilian compact pistols. While it is less powerful and considered less effective than mainstays such as 9x19mm or .45 ACP, it remains available in today’s market and has benefitted from advancements in firearms technology.


  • Low recoil: .380 ACP ammunition generates less recoil than 9x19mm, making it soft-shooting and easy to control, especially in small and compact handguns.
  • Compact guns: Most .380 pistols are lightweight, easy to conceal, and appropriate for self-defense, especially concealed carrying.
  • Low gun costs: Whether you need a primary concealed carry pistol or a backup gun, quality .380 pistols are available at lower prices than their equivalents in larger cartridges.


  • Ammo costs: Despite being smaller and less powerful than 9x19mm, average .380 ACP costs have historically been high, making it an expensive cartridge to practice with.
  • Limited gun capacity: Although the .380 ACP cartridge has similar dimensions to 9x19mm, few .380 guns feature high magazine capacities. The average .380 pistol has a capacity ranging between 6 and 15 rounds.
  • Limited effectiveness: Even the best self-defense .380 ACP ammunition remains less powerful than 9mm, .40, .45, or .357. .380 is often considered a “marginal” cartridge for self-defense due to its lack of energy.

Long Gun Calibers to Consider

Although rifles and shotguns are typically relegated to home defense or open carry, they are unquestionably more powerful, accurate, and easier to control than handguns. Below are some of the top caliber recommendations for personal defense long guns.

  • 56x45mm NATO / .223 Remington: 5.56mm NATO is the standard cartridge of the AR-15 platform. 5.56x45mm is inexpensive, generates low recoil, and is generally easy to shoot. It is one of the most popular self-defense rifle cartridges in America, largely due to the popularity of the AR-15. For these reasons, 5.56 or .223 are the most common answers to the question, “What is the best caliber for a rifle for self-defense?”
  • 62x39mm: This is the cartridge used by the original AK rifles, such as the AK-47 and AKM. Semi-automatic AK-platform rifles are popular alternatives to the AR-15, developing comparable power and ballistics to the .30-30 Winchester, the classic lever-action rifle cartridge.
  • .308 Winchester / 7.62x51mm NATO: Perhaps the most versatile rifle cartridge in the United States, the venerable .308 is known as 7.62x51mm NATO in military applications. A high-quality, semi-automatic .308 rifle may be one of the most versatile guns you can purchase. With the right ammunition for each, this caliber is viable for self-defense, hunting, precision target shooting, and SHTF applications.
  • 12 gauge: Prominent firearms expert Massad Ayoob described the 12 gauge shotgun as “perhaps the most efficient close-range killing machine in the world’s arsenal of small arms.” The 12 gauge shotgun, particularly when loaded with self-defense buckshot, is among the most effective and powerful weapons available for home defense or all other close-quarters applications.

Made your pick? Find the best self defense ammo for your caliber.

Self-Defense Education at Uppercut Tactical

At Uppercut Tactical, one of our critical missions is to help Americans prepare for any eventuality and protect themselves and their loved ones. Besides offering a wide range of practical self-defense knives, we also provide emergency supplies, medical kits, and comprehensive preparedness  and self-defense information to ensure you are ready for anything.


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