If you own a handgun, you know that it’s the ammunition that does the job. Firearms are simply the launching mechanism. Their purpose is to initiate the firing sequence, contain the explosion, and direct the bullet toward the target. To select the caliber and ammunition type most suitable for your intended application, it’s necessary to understand what’s available.
What is Caliber?
Caliber can either refer to a particular cartridge or an approximation of the bullet diameter. In firearms, the caliber refers to the diameter of the rifled bore, from land to land. Caliber may be expressed in hundredths of an inch (e.g., .22 caliber), thousandths of an inch (e.g., .357 caliber), or millimeters (e.g., 9mm).
In metric cartridge designations, there are often two numbers, for example, 9×19mm. The first number denotes the diameter of the bullet. The second indicates the length of the cartridge casing. Some metric designations also have letters, such as B, R, and SR. These indicate the type of cartridge case: belted, rimmed, or semi-rimmed.
Modern small-arms ammunition consists of self-contained metallic cartridges or rounds. The basic components of ammunition are as follows:
The bullet is the projectile — the part that the burning powder propels through the barrel toward the target. The purpose of the bullet is to inflict ballistic damage to the target, causing a specific action to result. In a defensive weapon, the desired action is incapacitation to stop the threat. In a hunting weapon, the priority is to kill the game animal as efficiently as possible. Bullet weight is typically measured in grains. A grain is equal to 1/7,000th of a pound, and there are 437.5 grains to an ounce.
The propellant charge. When ignited by the primer, the propellant burns or deflagrates due to its low explosive power. Modern powder propellants are smokeless in contrast to traditional black powder. Unlike black powder, which generates copious amounts of thick, white smoke, smokeless powder produces mostly gaseous combustion products.
The primer initiates propellant ignition when struck by the firing pin or striker. The firing pin, a thin metal rod with a rounded point, impacts the primer, causing the primary explosive contained therein to detonate. As the priming compound detonates, it projects incandescent particles through the flash hole in the cartridge case head into the propellant charge, igniting the propellant and firing the round.
The cartridge case is the part that holds everything else together in a self-contained, environmentally sealed, and impact-resistant package. In addition, the cartridge case expands on firing, obturating the breech. Cartridge cases are typically made of brass, aluminum, or steel.
Muzzle Velocity and Energy
When the primer ignites the propellant charge in the cartridge case, the burning propellant generates high-pressure expanding gases. These gases apply equal pressure against all surfaces. The force applied against the breech face through the cartridge case head is the bolt thrust. This is the source of energy in blowback- and recoil-operated firearms. It’s also what causes you to feel the weapon recoil against your hand or shoulder.
As the gases apply pressure against the bullet, they accelerate it through the barrel until it leaves. The velocity at which the bullet leaves the barrel is the muzzle velocity. The barrel length has a direct influence on the muzzle velocity. In the United States, the muzzle velocity is expressed in feet per second (ft/s). Outside of the U.S., muzzle velocity is expressed in meters per second (m/s). The muzzle velocity directly affects the external ballistics of the projectile, including its trajectory, effective range, kinetic energy, and terminal performance.
The kinetic energy of the bullet at the muzzle is the muzzle energy. In countries that use imperial or U.S. units, kinetic energy is expressed in foot-pounds force (ft-lbs.) In those countries that use the metric system, kinetic energy is expressed in joules (J).
The bullet’s kinetic energy plays an essential role in the terminal effects of the bullet, contributing to wounding performance.
Handgun Caliber Guide
There are a wide variety of handgun cartridges to choose from. Before you can select the best handgun and caliber combination to suit your specific needs, it’s essential to know some of the most common handgun calibers and what they’re used for.
.22 Long Rifle
The lightest and least powerful caliber on the list, the .22 Long Rifle is the world’s most popular cartridge. A rimfire round developed in the 19th century, the .22 Long Rifle is known for being widely available and inexpensive — under normal circumstances — light-recoiling, accurate, and relatively quiet. In a pistol, the .22 Long Rifle is used extensively for recreational target shooting, including plinking. However, several firearms manufacturers, such as Glock, also produce .22-caliber variants of centerfire handguns for familiarization firing.
One of the .22’s strong suits is that it helps teach the fundamentals of marksmanship to new shooters due to its low recoil and minimal report, making it useful for small game hunting or varmints.
Introduced in 1908, the .380 Auto or ACP, or Automatic Colt Pistol cartridge is designed for compact, highly concealable handguns for engaging targets at close range. As the .380 ACP generates less bolt thrust than the 9mm Luger, it’s often more controllable in lightweight weapons. Widely considered the minimum acceptable pistol caliber for self-defense, the .380 ACP typically uses bullets weighing between 90 and 100 grains.
9×19mm Parabellum (9mm Luger, 9mm NATO)
Designed by Georg Luger in 1902, the eponymous 9mm Luger is probably the most popular centerfire semi-automatic pistol and submachine gun cartridge globally, including among law-enforcement agencies. Moderately powerful, controllable, and accurate, the 9mm is a good choice for self-defense. In 1985, the 9mm Beretta M9 replaced the venerable .45-caliber M1911A1 in U.S. military service. Typical bullet weights in this cartridge are 115, 124, and 147 grains.
Introduced in 1990, Smith & Wesson and Winchester developed the .40 S&W jointly to duplicate the ballistics of the reduced-pressure 10mm FBI load in a cartridge with a shorter case. The result is a .40-caliber round that’s compatible with medium-framed handguns designed for the 9mm round but which delivers a heavier bullet — 165 and 180 grains being the most common. A favorite among law enforcement, the first handguns chambered in this round were the Glock 22 and 23.
.45 ACP (.45 Auto)
An American classic, the .45 ACP (Automatic Colt Pistol) cartridge has been in use since the adoption of the M1911 pistol 110 years ago. While primarily a semi-automatic pistol cartridge, the .45 ACP, like the 9mm, has also been used extensively in submachine guns, such as the Thompson, M3 Grease Gun, and MAC-10.
The .45 ACP cartridge is inherently subsonic and uses bullets weighing 185, 200, and 230 grains. Prized for its stopping power, the .45 continues to have a loyal following. While controllable in a full-size service pistol, some shooters may find the recoil challenging to manage in highly compact weapons. Nevertheless, the .45 remains an excellent round for self-defense.
Introduced in the ill-fated Dornaus & Dixon Bren Ten, the 10mm Auto cartridge is a modern powerhouse. In its full-power loadings, the cartridge can meet and exceed the ballistic performance of the .357 Magnum cartridge, delivering a heavier bullet at a comparable velocity. In its reduced-pressure loads, it’s still a moderately powerful defensive caliber, which is why it attracted the attention of the FBI following the disastrous shootout in 1986 Miami.
Making its debut in the FN P90 personal-defense weapon (PDW), the 5.7mm cartridge propels a lightweight, low-caliber bullet to rifle-like velocities in a weapon the size and weight of a submachine gun. In handguns, such as the Five-seveN, the 5.7mm round allows for an accurate, low-recoil, high-capacity weapon — 20 rounds per magazine. The 5.7mm exceeds the average muzzle velocities of the .22 Winchester Magnum Rimfire in a handgun barrel.
The .38 Special is a rimmed, centerfire revolver cartridge developed by Smith & Wesson and introduced in 1898 as a more powerful alternative to the .38 Long Colt, which had shown dismal performance in the Philippines. Once the default cartridge of police service revolvers, the .38 Special remains a popular choice for target shooting and use in snub-nosed revolvers for concealed carry.
In 1935, the .357 Magnum entered the scene in the Smith & Wesson Registered Magnum. Consisting of a lengthened .38 Special cartridge loaded to considerably higher pressures, the .357 Magnum was a standard police service-revolver cartridge for decades. Although law-enforcement agencies in the U.S. no longer issue revolvers as primary sidearms, the .357 Magnum continues to be a popular round for self-defense and hunting among private citizens. In lightweight, snub-nosed revolvers, the .357 Magnum generates fierce recoil, muzzle flash, and blast.
A .357 Magnum revolver can chamber and fire .38 Special cartridges; however, the reverse is not true.
Introduced in 1956, the .44 Remington Magnum was once hailed as the world’s most powerful production handgun cartridge. While that is no longer true, as many other pistol calibers soon eclipsed it, it remains a powerful revolver and carbine cartridge suitable for hunting and defense against dangerous fauna. However, its usefulness as an anti-personnel self-defense cartridge is limited due to its recoil, which requires a large, heavy-framed weapon to manage properly. This cartridge uses bullets weighing between 180 and 300 grains — 240 being common.
As the .44 Magnum is based on a lengthened .44 Special cartridge, .44 Magnum revolvers can fire .44 Special ammunition, which operates at lower chamber pressures.
For highly specialized purposes, such as hunting large, dangerous game and protection against grizzly, brown, and polar bears, there are a variety of large calibers available for the handgunner. These include the following:
The .454 Casull began as a wildcat cartridge in the late 1950s. Based on a lengthened .45 Colt cartridge, the .454 Casull achieves higher muzzle velocities than +P .44 Magnum loads using bullets weighing 240 grains or more.
.475 Wildey Magnum & .44 Auto Mag Pistol (AMP)
The .475 Wildey Magnum and .44 Auto Mag Pistol cartridges are powerful semi-automatic pistol cartridges based on necked-down rifle cartridge casings (.284 Winchester and .30-06/.308 Winchester, respectively). Although rare these days, both cartridges, and their accompanying handguns, made silver-screen debuts in Death Wish 3 and Sudden Impact.
.50 Action Express
This caliber is mostly associated with the Desert Eagle. Typically loaded with bullets weighing between 300 and 325 grains, the .50 Action Express achieves muzzle velocities in a handgun of between 1,400 and 1,550 ft/s, producing 1,400–1,600 ft-lbs of muzzle energy.
.500 S&W Magnum
One of, if not the, most powerful production handgun cartridges in the world, the .500 S&W Magnum meets or exceeds the power of a 12-gauge shotgun or full-power service rifle in a revolver.
Common Bullet Types
Full Metal Jacket (FMJ)
A full metal jacket is a round- or flat-nosed bullet consisting of a lead-alloy core enclosed in a copper, cupro-nickel, or brass jacket. The primary purpose of the jacket is to protect the core against deformation and heat. Exposed lead bullets can melt or deposit fouling in the barrel when not shielded from the intense heat of burning powder and friction of high-velocity acceleration. Many full metal jacket bullets have an exposed base.
Full metal case (FMC) is a type of complete metal jacket design in which the jacket also encloses the base of the bullet. This reduces the extent to which vaporized lead can enter the air, causing less pollution in indoor firing ranges. FMJ bullets are best suited for target practice.
Jacketed Hollow Point (JHP)
Hollow point bullets are best suited for personal protection. A jacketed hollow point has an open cavity in the nose designed to promote expansion in soft tissue. As the hollow point expands, the diameter of the bullet and its frontal surface area increase. This increases drag, transfers more kinetic energy to the target, and crushes more tissue. The result is more permanent and temporary wound cavitation and less penetration. Hollow point bullets are also available in two additional subtypes:
Lead Hollow Point (LHP)
Lead hollow-point bullets do not have a protective jacket. As a result, the LHP will deposit more fouling in the barrel and tends to be more susceptible to deformation.
Semi-Jacketed Hollow Point (SJHP)
An SJHP has a partially jacketed nose to promote a more rapid expansion rate than the fully jacketed type without the limited penetration and increasing fouling associated with LHP bullets.
Open Tip Match (OTM)
While OTM bullets somewhat resemble JHP bullets, they’re not designed to expand. The open tip in the jacket is the aperture through which the manufacturer pours the molten core metal. This production process ensures a high degree of uniformity and precision. OTM ammunition is designed to maximize accuracy in rifles.
A ballistic tip is a jacketed hollow-point bullet with a polymer insert in the nose cavity. The insert is usually pointed and provides a more aerodynamic profile to the projectile for increased accuracy. In lever-action rifles fed from tubular magazines, in which the cartridges are loaded nose to primer, ballistic tips allow the use of spitzer ammunition without the risk of causing an unintentional discharge under recoil.
Jacketed Soft Point (JSP)
Jacketed soft-point bullets are jacketed projectiles with an exposed lead nose. A JSP bullet can be considered a hybrid between FMJ and JHP. FMJ bullets are generally non-deforming, which limits terminal wounding performance. JHP bullets cause more tissue disruption but are more limited in penetration.
The wadcutter is a sharp-shouldered cylindrical bullet with a flat nose designed for target shooting. The bullet’s design allows it to punch perfectly circular holes in paper targets for accurate scoring. In a self-defense context, the wadcutter can be a viable alternative to JHP bullets as self-defense ammo in short-barreled firearms that cannot consistently meet the expansion threshold.
In its standard configuration, the semi-wadcutter bullet retains the sharp shouldered conical base of the standard wadcutter, adding a tapered or truncated cone with a flat nose to the front.
What to Consider When Choosing a Handgun Caliber
Rimfire vs. Centerfire
Rimfire cartridges use a priming compound inside the cartridge case rim to ignite the propellant charge in the cartridge. Centerfire cartridges use a removable primer centrally located in the case head.
Rimfire cartridges are generally less powerful, can’t be as easily reloaded, and can be unreliable. How reliably the primer detonates is a critical factor in a defensive firearm.
Performance and Recoil
Every choice of handgun is an attempt at balancing different and sometimes competing interests. If you want to conceal a handgun, it has to be relatively compact and lightweight. The lighter a handgun is, the more it will recoil. The more compact and concealable a handgun is, the more difficult it is to control, as there’s less gripping surface. You’ll need to determine the appropriate caliber according to these factors.
Your Shooting Ability
Some shooters find that they can fire some calibers more accurately than others. Regardless of caliber, you must practice with it regularly if you rely on a handgun for self-defense. If you find that, once you’ve developed your marksmanship skills, you can more consistently hit a man-size target with a 9mm than a .45, that may be the superior choice for you.
A magazine is designed to store multiple cartridges under spring pressure for feeding into a firearm. Handguns typically use detachable box magazines, which can be divided into two categories: single stack and double stack.
A single-stack magazine has a single feeding column in which cartridges rest one on top of another in a vertical line. These magazines allow for narrower pistol grips at the expense of capacity. A higher capacity in a single-stack magazine requires an increase in height.
A double-stack magazine has a staggered feeding column. Double-stack magazines allow you to increase the magazine capacity by increasing width rather than height.
In semi-automatic pistols for self-defense and competitive target shooting, caliber affects the magazine capacity. For example, a 9mm handgun typically has a higher magazine capacity than a .45-caliber handgun.
Cost and Availability
Ammunition prices and availability fluctuate due to several factors, but when these are stable, they can inform you regarding the long-term viability of your ammunition choice.
Find a Reputable Dealer
At IFA Tactical, we sell a wide variety of handgun ammunition to suit every purpose, from target shooting and hunting to self-defense. If you need help deciding which caliber or ammunition type to choose, don’t hesitate to give us a call. Our knowledgeable staff can offer advice and recommendations.