Handguns, like all types of firearms, fire a variety of different types of ammunition. The type of ammunition you need varies considerably depending on your intended application.
What is Ammunition?
A firearm is a launching mechanism for a projectile. Ammunition is the bullet or shot charge that causes damage to the target. Modern handgun ammunition comprises of cartridges or rounds which consist of the following four components:
The bullet is the projectile and the only component to leave the barrel intact. When the bullet enters the bore of a modern firearm, the rifling causes it to spin. This rotation stabilizes the bullet gyroscopically, causing it to fly farther and more accurately.
The gunpowder is the propellant charge that, when ignited, generates high-pressure expanding gases. These gases force the bullet free from the cartridge case and drive it through the barrel. Modern cartridge ammunition use smokeless powders, which produce fewer combustion products than black powder.
The cartridge case is the part that holds all the other components together in a durable, self-contained package for loading. On firing, the case expands, obturating the breech. The cartridge case also acts as a heat sink.
The primer is an essential component of the ignition system. When struck by the firing pin, the primer detonates, igniting the propellant charge and initiating the firing cycle.
Parts of a Cartridge Case
There are other terms that relate to ammunition that you should know. These include the following:
The mouth of the cartridge case is the opening that receives the propellant charge and bullet.
In bottlenecked cartridges, the shoulder is the part of the case between the neck and the body that slopes downward. In some firearms, this is also the headspacing point.
The part of a bottlenecked cartridge case that extends upward from the shoulder.
The rearmost part of the cartridge case contains the base, rim, headstamp, and primer pocket.
The face of the case head that contains information, such as the caliber and manufacturer.
What is a Caliber?
The caliber of a bullet denotes its diameter in either inches or millimeters. Caliber also refers to the inside diameter of the barrel, usually from groove to groove. In inches, caliber is expressed in either hundredths (e.g., .45 caliber) or thousandths (e.g., .308 caliber). In millimeters, there are typically two values. In the designation “9×19mm,” for example, the first number denotes the bullet’s diameter, and the second denotes the length of the cartridge case.
You may ask, “What is a bullet grain?” “Grain,” in the context of ammunition, refers to a unit of weight measurement equivalent to 1/7,000th of a pound that originated from measuring grains of wheat or barley. One ounce is 437.5 grains. In metric units, 15.43 grains equals one gram. In the U.S., bullet and powder weights are primarily expressed using grains.
For example, the most common bullet weights for the .45 ACP cartridge are 185, 200, and 230 grains. In 9mm, the most common bullet weights are 115, 124, and 147 grains.
Types of Cartridge Cases
There are a variety of different types of handgun ammunition, each serving a different purpose.
In a rimless cartridge, the rim is the same diameter as the base of the cartridge case. There is a recess encircling the casing above the rim called the extractor groove. Rimless cartridges typically headspace on the mouth and are designed to feed reliably in semi-automatic and fully automatic actions.
In a rimmed cartridge, the rim exceeds the diameter of the case body. Rimmed cartridges are primarily designed for use in revolvers, as the rim provides a surface for the extractor star to impinge against for unloading. The rim is also the headspacing point.
In a rebated-rim cartridge, the rim diameter is less than that of the base. The purpose of a rebated-rim cartridge is to allow caliber conversion using the same breech face. An example would be the .50 Action Express used in the Desert Eagle. The .50 AE uses the same rim diameter as the .44 Magnum; therefore, to convert a .50 AE Desert Eagle to .44 Magnum, and vice versa, only a barrel change is necessary.
A hybrid design, the semi-rimmed cartridge case is designed for use in semi-automatic pistols. As the rim protrudes less than in rimmed designs, it interferes less with reliable feeding in detachable box magazines.
There are many bullet types to choose from, depending on the type of target you intend to shoot. The following are the most common types of ammunition used for law enforcement, military service, private self-defense, and recreational and competitive target shooting.
Full Metal Jacket (FMJ)
Full metal jacket, also known as ball ammunition, is primarily intended for military service and target practice. Introduced in the late 19th century, full metal jacket ammunition typically consists of a lead-cored projectile enclosed in a copper jacket.
The jacket’s purpose is to protect the core against deformation, heat from the burning propellant, and friction from the bore. This also reduces fouling in the barrel. FMJ bullets usually have either rounded or flat noses. FMJ bullets also tend to feed more reliably in semi-automatic actions.
Full Metal Jacket vs. Total Metal Jacket (FMJ vs. TMJ)
What’s the difference between full metal jacket (FMJ) and total metal jacket (TMJ) ammunition? The difference is simple: in a TMJ projectile, the bullet is fully enclosed, including the base. In FMJ projectiles, the base may be exposed.
For their intended purposes, this difference doesn’t affect performance. However, if your priority is to minimize lead exposure, a total metal jacket projectile with a lead core will protect the core more effectively against the high-temperature propellant powder gases. The result is less vaporized lead in the atmosphere, which is ideal for indoor shooting ranges.
Lead Round Nose (LRN)
Jacketed Hollow Point (JHP)
Wadcutter vs. Hollow Point (WC vs. JHP)
Armor Piercing Bullets (AP)
Armor-piercing ammunition is not readily available to private citizens in the United States and is restricted to law enforcement and military use. The purpose of armor piercing bullets is to penetrate soft body armor, such as Kevlar ballistic vests.
Bullets composed of soft metal alloys, such as lead, often deform on impact with Kevlar and other bullet-resistant aramid or composite materials. AP bullets typically have a core made from a hard metal alloy that resists deformation, concentrating its energy on the point.
If you own a handgun or are thinking of buying one, the ammunition that you choose can play a vital role in your success or failure. At We the People Holsters, we understand the importance of selecting the correct caliber and load for your self-defense handgun. We also offer a wide variety of high-quality holsters so that you’ll be prepared for anything.