Essential Handgun Parts: Learn What You Absolutely Need

Ever wanted to know every single part of a handgun and the difference between semi-automatic pistols and revolvers?

If you have, chances are you might have run into a problem. There’s tons of misinformation and interchangeable usage of vocabulary about firearms, especially when it comes to handguns and pistols. We’ll thoroughly explain the differences and gun parts below.

That’s why, in this guide, we’ll take a good look at handgun parts, the types of handguns and their differences, how they work, how to disassemble them, and more.

We’ll also share a few buyer’s purchasing tips that’ll help you if you’re on the search for the right firearm.

To properly inform you about the basic parts of a handgun, we’ll take a look at several different types of handguns and pistols.

Each and every part has a specific function that makes a handgun work. A responsible firearm owner has the duty to know how they work and be able to identify every part of the handgun, not just the major ones.

Basic Firearms Categories

We know that firearms fall into three basic types: rifles (break-action, lever-action, pump-action, bolt-action, and semi-auto), shotguns (pump-action, semi-automatic, and break-action), and of course, handguns.

When portability and quick self-defense or home defense is in question, handguns are hands-down the preferred category of firearms as a concealed carry solution for close-quarter combat. Law enforcement officers carry handguns as their primary self-defense tool, as well.

They are easy to conceal, easy to operate, and are the number one choice when size and weight are important. They’re easy to hide from the public view using ankle holsters, or even a handbag or bra holster.

Handguns are easy to use, but they are somewhat difficult to master, and that’s why they’re popular at competitive target practice and shooting ranges.

If you’re considering buying a handgun, be sure to get yourself a concealed carry permit, a handgun safe, and a holster, as well as concealed carry insurance.

The broadest definition – a handgun, or in some cases, a pistol, is a firearm designed to be held in one or two hands without being braced against the shoulder.

The words ‘pistol’ and ‘handgun’ are interchangeably used, though pistol is technically a subcategory of a handgun, i.e. a type of a handgun. Old-fashioned usage still persists in some US states, and ‘pistol’ sometimes refers to semi-automatic handguns for some reason.

This confusing nomenclature is probably rooted in obsolete language nuances. Case in point: the infamous ‘clip vs. magazine’ battle still wages on, thanks to gun nerds.

Simply put, a pistol is always a handgun, but a handgun is not always a pistol.

Pistols are handguns with only one chamber integral to the barrel. Popular handguns like semi-automatic pistols have one chamber. Revolvers have multiple chambers (usually six), and so they’re handguns, but not pistols. So basically, pistols and revolvers are different types of handguns.

​Types of Handguns

There are three basic types of handguns:

• Single-shot handguns (muzzleloaders)
• Revolvers
• Semi-automatic pistols

These are the main types of handguns, but you can find many variations and models for each type. Some categorizations of handguns only depend on their trigger action. So, you can also divide handguns into:

• Single-action only (SAO)
• Double-action (DA)
• Double-action only (DAO)
• Double-action/Single-action (DA/SA), and
• Striker-fired handguns (SF)

But, we’ll stick to the first categorization.

The Difference Between Single-Shot, Revolvers, and Semi-Automatic Handguns

Single-shot pistols are revolvers with rotating cylinders, and their frame is usually what the barrel is attached to. They contain the same trigger group depending on the model. If it’s a bolt-action handgun, it can be attached to the receiver.

Most single-shot pistols are used exclusively for hunting and target practice and are not very effective for self-defense. Single-shots are uncommon, and we’ll talk about them another time.

Revolvers are usually six-shooters with rotating cylinders for ammo, and they rely heavily on the hammer. They can be single-action or double-action. The barrel can be a break-open action where you load the rounds into the barrel.

Single-action means you have to cock the hammer for each round you shoot. Double-action means the trigger can be squeezed for each round without manually cocking the hammer, but it’s slightly heavier this way.

Semi-automatic pistols can also be single or double-action. They use gas or recoil energy for round cycling. Chambering rounds cock the hammer, and gun cycling cocks it when you fire a round. They use one fixed firing chamber, and after the round is fired, the recoil mechanism automatically ejects the shell casing and reloads.

The three basic parts of a handgun remain nearly the same for most semi-auto handguns.

If you need help with properly storing and keeping your guns safe, you can check out our best handgun safes guide here.

Muzzleloader Handguns

Here’s a rarely-mentioned type of handgun.

Muzzleloaders used to use flintlocks, and they were the very first to be loaded from the open end of the barrel, or the muzzle. Modern handguns use part of the barrel closest to the firing mechanism, also called ‘breach’.

The first thing that comes to mind are ‘pirates’.

These ancient firearms are the ancestors of modern handguns, but now, they’re a museum type of weapon.

Muzzleloaders are outdated and impractical. They are like cannons that can be fired by hand, and they kick like a mule. But, they have historical value, are sought after by collectors, and are sometimes used by historical reenactors.

Depending on whether it’s a semi-automatic pistol or a revolver, a handgun has three basic groups of parts.

The main parts of a handgun are the action, the frame or the receiver, and the barrel:

• The frame, or receiver, is the skeleton of the handgun. It’s the main metal housing that holds and connects all parts together. It can contain internal components like the hammer, action, and firing mechanism. It also serves as the grip or handle of the handgun.
• The action, as the name suggests, are the moving parts responsible for loading, unloading, firing, and discharging the cartridges. It’s also known as the trigger group.
• The barrel is the metal tube that the bullet travels through.

It’s also good to know that common handguns like the Glock 19 rely on magazines that are put in the stock or grip, while revolvers like the Smith & Wesson 19 are fed rounds directly into their break-open cylinders.

We’ll take a look at the semi-automatic pistols’ parts, and then we’ll take a look at the revolver’s parts.

Here are the components of the semi-automatic pistol and how they work.

The Frame

The frame is the main part of the semi-automatic pistol, and it holds all the other parts of the weapon.

They are usually made of metal, but Glock handguns are famous for their comfortable plastic polymer frames.

The Grip

The grip, or stock, is the part you hold in your hand. It can be textured with various rubber or other grips for comfort, stability, ergonomics, and a sturdy, non-slide grasp.

For semi-automatic pistols, it houses the magazine, and the bottom of the grip is open and is called a loading port or a magazine port.

The Trigger

The trigger is a metal piece that starts the firing sequence. It can be pulled to the rear and, depending on the action type, one or two things will happen.

If it’s a double-action handgun, the hammer pulls back and the cylinder rotates, aligning the next chamber with the barrel. Squeezing the trigger further releases the hammer and it strikes the firing pin which fires a round.

If it’s a single-action, you need to manually cock the hammer if you want to shoot.

The Trigger Guard

This is a metal piece that guards the trigger, preventing accidental discharge. It’s designed to keep your finger away from the trigger if you’re not planning to shoot.

The Barrel

The barrel is the metal tube affixed to the frame through which the bullet travels. It can be either pinned or screwed into the frame.

The barrel features a forcing cone to guide the round through the bore, perfectly centered. The inside of the barrel has a spiral pattern of grooves which make the bullet spin for increased accuracy. Inside the barrel, there are the rapidly expanding gases that propel the bullet via pressure when the powder is ignited.

Revolver barrels can be fitted with front and rear sights.

The Sights

The front sights and rear sights are located atop the handgun and are used for aiming when properly aligned.

Some sights can be metal, polymer, fiber optic, or incandescent.

The Breech

Breech literally means rear, and it’s the back end of the barrel. It’s close to the firing mechanism.

The Bore

The bore is the interior of the barrel, and it’s lined with spiraling grooves which spin the bullet for accuracy and speed.

The diameter of the bore is called a ‘caliber’, and the most common handgun calibers are .380 ACP, 9mm, .45 ACP, .40 S&W, etc.

The Muzzle

The muzzle is the front end of the barrel.

Never point the muzzle at anyone, even when the gun is empty.

The Hammer

The hammer is behind the cylinder/slide. When you pull the trigger, the hammer strikes the firing pin and drives it into the cartridge primer. The primer can be rimfire or centerfire, and it explodes and ignites the bullet, propelling it thanks to the pressure out of the muzzle.

The Firing Pin

When struck by the hammer, the firing pin hits the primer of the round, so the chemical reactions and the pressure propel the bullet out of the muzzle.

The Magazine

The magazine contains multiple rounds that are fed into the action via spring tension. They can be attachable or detachable, depending on the firearm. Magazines are one of the reasons why semi-autos can fire and reload faster than revolvers.

Don’t confuse magazines with clips. Clips feed into magazines, while magazines feed the weapon.

The Magazine Release

The magazine release is a button, neatly located behind the trigger guard.

When you load the mag, you can hear a click. The sound is the magazine release mechanism locking the mag into place. The magazine well, or the magwell, locks the magazine into place, making sure the cartridges feed into the chamber.

If you want to remove the magazine, just push the magazine release.

The Slide

The slide is the topmost part of the semi-automatic pistol.

You pull back the slide and release it to load a cartridge into the chamber or when you’re disassembling the handgun. You can also mount front sights and rear sights on the slide.

The slide works when you fire a bullet: the recoil forces the slide to the rear, and the extractor on the slide removes and ejects the spent cartridge. The action then re-cocks the hammer, and as it slides forward, the slide pushes the next cartridge from the mag and into the chamber for the following round.

The Takedown Lever

The takedown lever is located above the trigger, below the slide. It releases the slide and barrel for disassembly. The lever retains the slide, the bolt, or the barrel, and some levers are different, depending on the manufacturer.

The Slide Stop or Slide Release

The slide stop or the slide release is a lever behind the takedown lever.

Its function is to lock the slide in the open position after the last round is fired, and pushing down the slide releases it, allowing it to move forward.

This is used when you want to disassemble the handgun.

The Safety or Decocking Lever

The safety mechanism, or decocking lever, is usually located below the rear sight, and it can sometimes be a button.

It works when a handgun has the hammer cocked, the shooter can lower the hammer via the decocking lever. When it’s in the safe position, the pistol is unable to fire, and you must pull the lever up if you want to shoot.

Not all semi-automatic pistols have an external safety. Some Glock models have a safety that can only be deactivated when the trigger is pulled.

The Ejection Port

The ejection port is an opening through which the casings come out.

The Recoil Spring and Guide

The recoil spring and guide is usually one single connected unit, and are located inside the handgun.

When the slide is forced back by the recoil when fired, the recoil compresses the recoil spring which returns the slide forward and places the next round.

The six-shooter revolver is built differently. Unlike the semi-auto handgun, it utilizes its rotating cylinder to set up rounds.

A single-action revolver needs to be cocked after each round, while a double-action just needs a stronger trigger pull to fire the rounds.

The Cylinder

The main part of the revolver frame is the cylinder. It’s a part that has a revolving mechanism that lines up the bullets for firing.

Common revolvers use 6-chamber rounds as a general standard, and the most popular revolver calibers are the .357 and the .44. You also have 9mm revolvers, as one of the more widespread handgun types amongst law enforcement units.

The mechanism is simple and reliable. The revolving cylinder moves to line up the chambered rounds as you pull the trigger and the hammer draws back. After every shot, the mechanism aligns another round, and you need to manually reload, bullet by bullet.

Common revolvers reload the rounds via release, and the cylinder drops the spent cartridges. If you’re not a fan of slow reloading, there are high-quality speed loaders on the market today, which makes things a lot easier.

Cylinder Release

The cylinder release is actually a slide lever that can be pressed or pushed forward to slack the cylinder to reload the next six rounds. It uses a spring-loaded mechanism that rarely malfunctions.

The Ejector Rod

The ejector rod is located in the center of the cylinder. It spins on a fixed axis and allows the cylinder to rotate after each round.

Extractor

The extractor is a spring-loaded part, located at the end of the rod. It’s used to catch the spent cartridges.

Simply push back on the front of the ejector rod as the extractor pushes the fired rounds from the cylinder. Then, the extractor pushes out the spent cartridges and makes the cylinder ready for a new reload.

Since there are many models of handguns, make sure you read the owner’s manual on how to take care and disassemble your handgun, and follow these simple rules:

• Never point the muzzle at anyone, even if the gun is empty.
• Keep your finger off the trigger until you are absolutely ready and sure to shoot.
• When aiming, carefully consider your target and what’s in store whether or not you shoot.

You’ll rarely see a disassembled revolver for cleaning, but semi-automatic pistols require constant disassembly for proper cleaning.

Simply remove the magazine via mag release, use the takedown lever to release the slide and barrel. Then, remove the recoil spring and guide.

Here are some frequently asked questions about the parts of a handgun.

The sole purpose of this guide is to clear up inconsistencies and to better inform you when the time comes to look for proper aftermarket customization. Proper working knowledge about the handgun and its components is necessary for any responsible gun owner.

As we mentioned, the three main parts of the handgun vary between different models, but you can always divide them as you like. Semi-autos have slides, revolvers have cylinders.

We must understand the many pieces and how they work in order to better take care of our guns and ourselves. Professional communication is key, and this guide will allow you to learn the components for better reference.