Pistol Anatomy: Everything You Need to Know!

How well do you know your pistol anatomy? If you’re new to the world of semi-automatic pistols and the like, probably not very well. That’s why I’ve decided to write this article about the major components that make up a semi-auto handgun.

You’ll find most (if not all) of the parts mentioned below in modern handguns, whether double-action, hammer-fired, or striker-fired handguns or used by law enforcement officers. Now, let’s dive in!

Three Main Parts of a Handgun

When you open up a handgun, its parts can be divided into three basic groups: the action, the frame, and the barrel. Let’s learn about each one:


The frame connects all the parts of the handgun. The other two major groups (the action and the barrel) and other basic parts like the firing mechanism are part of the frame. So you can think of it as the skeleton of the gun, with the other parts fleshing it out.


The action is also called the trigger group. As its name suggests, it consists of the gun’s moving parts, which make actions like loading and unloading, firing, and ejecting spent casing possible.


Handgun barrels are metal tubes through which bullets travel when you pull the trigger. They’re usually screwed or pinned to the handgun’s frame, and their length can affect how far and fast a bullet flies.

Other Parts of a Semi-Automatic Pistol

Now that you’re aware of a handgun’s three main parts, let’s go deeper and see the other parts that make semi-autos tick.


The barrel’s interior is called the bore. It’s a metal tube lined with spiraling grooves which make the bullet spin, improving its speed and accuracy. Meanwhile, the bore’s diameter is called the gun’s caliber, referring to the size of bullets that can travel through it.


Also called the decocking lever, you’ll find a handgun’s safety mechanism beneath the rear sight. The safety prevents accidental discharges from occurring when you have the hammer cocked, as the gun won’t be able to fire when the safety’s engaged. Therefore, an accidental trigger pull won’t make the gun fire until you pull the safety lever up.

It’s worth noting that some pistols (like particular models by Glock) don’t have external safety.


Handguns come with either a front sight, a rear sight, or both. Front and rear sights are located on the top part of the firearm. While front sights are closest to the gun’s muzzle, rear sights are behind the gun’s slide.

You use sights to aim, and they can help improve your firing accuracy. Also, sights can be fixed or adjustable, illuminated or non-illuminated, and marked or unmarked.


The trigger is the metal part of the gun closest to the grip. When you pull the trigger backward, it begins the process that causes the gun to fire. By the way, the shooter’s index finger is often colloquially referred to as their trigger finger.

Trigger Guard

A pistol trigger is always accompanied by a trigger guard, which prevents accidental discharges from occurring.


The slide is the top part of semi-autos that moves when you fire a handgun. It houses the firing pin, the gun’s barrel, the guide rod, and the extractor.

When you fire a shot, it makes the top part of the firearm recoil or slide backward and then slide forward to its original position (thanks to spring tension), hence the name. It’s part of a complex mechanism that, along with the ejection port, ejects the spent bullet casing and loads the next round into the gun’s chamber while rearming the firing pin.

Slide Release

The slide release, slide stop, or slide lock keeps the slide from moving when you’re out of available ammunition. As a result, you won’t be able to fire a new round until you reload. It’s usually located on the firearm’s side and lets you know when your magazine is empty when the slide locks in a rearward position.

Recoil Spring

As mentioned above, the recoil from firing a handgun causes the slide to move backward before returning to its original position. The recoil spring aids this movement and functions, whether you fire multiple rounds in rapid succession or a single one.

Takedown Lever

Located in front of the slide release and higher than the trigger, the takedown lever helps disassemble the barrel and slide.


A cartridge is a case containing propellant, powder, primer, and bullet. It’s more common to hear it called a round.

Accessories Rail

Using the gun’s accessories rail, you can mount tactical accessories on your handgun, like lasers and flashlights.


The magazine houses your handgun’s ammo. Its capacity determines how many rounds the firearm can hold. You can remove the magazine from the pistol using the magazine release, enabling you to inspect a loaded magazine or replace an empty one.

Magazines come in two capacity types: single stack and double stack. Single stack magazines hold less ammo but make the firearm lighter. Meanwhile, double-stack magazines have a higher storage capacity, resulting in a heavier gun. Additionally, the magazine has multiple chambers in revolvers, and the cylinder rotates.

Magazine Well

Aside from revolvers, most handguns have a hollow part underneath the handle where you can slide a magazine in. This space is called the magazine well. You should hear a satisfying click once the magazine has been secured by the magazine release (below), though it wouldn’t hurt to tap the magazine to check if it’s properly secured.

Magazine Release

Behind the trigger guard of most handguns, you’ll find a tiny button called the magazine release. As its name suggests, it releases the magazine. However, this part of the gun pulls double duty by holding a magazine in place when you slide one into the pistol’s magazine well.

Magazine Spring

Handgun cartridges are spring-loaded to the gun’s chamber, thanks to the magazine spring. When you fire a round, the spring moves the next cartridge into position.


The hammer is positioned at the rear of the slide. Pulling the trigger makes the hammer strike the firing pin, driving it into the cartridge primer.

On single-action handguns, you have to manually cock the hammer before firing, whereas on double-action handguns, the hammer cocks automatically when you pull the trigger. Meanwhile, striker-fired handguns don’t have hammers.

Firing Pin

Once hit by the hammer, the firing pin hits the primer, propelling the bullet out the muzzle with a combination of a chemical reaction and pressure.

Ejector Rod

The ejector rod ejects cartridges when you fire the gun. It’s located underneath the barrel of the firearm.


The muzzle is the end of the gun where projectiles (bullets) emerge when you squeeze the trigger. In other words, it’s the part of the gun that you point at your target. Some muzzles can be fitted with a silencer to reduce noise when you fire a shot.

It can be extremely dangerous to point a muzzle at anyone or thing you don’t intend on “stopping,” so refrain from doing so, even if you think the gun is empty.

Ejection Port

When you fire a gun, the empty bullet casings fly out the top when the bullet travels through the barrel. The ejection port is the opening through which the bullet casings are ejected.


The tang or beaver tail is a small protrusion at the gun’s rear that protects your shooting hand from the movements of the slide. Additionally, it serves the purpose of helping to manage recoil when you fire a shot.


As the name suggests, the grip is the part of the gun you hold. Your fingers go around the front of the grip while the back strap sits in your palm. Some grips are textured with rubber to make them comfortable.

On a semi-automatic pistol, the butt of the grip can be opened as grips on these firearms house the magazine.


Armed with the knowledge in this article, you should be able to identify the various components of a handgun easily. So whether you’re getting one for sport or self-defense, you’ll know your way around the gun, making maintenance a breeze.