How Guns Work

A super quick explanation of how guns work.

We’ll begin with the easy definition of what is a gun, different components of the bullet cartridge, some gun actions, and loading mechanisms.

What a Gun is

At its core, guns are things that launch projectiles of some sort at high speed.  The first guns were just tubes with explosive and a projectile…think cannons.

Modern guns have come a long way.

Cartridges

What most people think of as “bullets” are actually “cartridges” that include the bullet, a casing, powder, and a primer.  The primer is first ignited which causes a small explosion, which then burns the rest of the powder, creating lots of pressure that moves the bullet out of the gun.  The bullet is just the projectile that shoots out of a gun, not the entire object.

Parts of a Bullet Cartridge
Parts of a Bullet Cartridge

Here you can see the expanded view of a typical rifle cartridge. Quarter for size.

308 Cartridge Parts
308 Cartridge Parts

And here are cross-sections of a variety of pistol/rifle cartridges.  Not to scale with each other.

Cross Section of a Bullet Cartridge
Cross Section of a Bullet Cartridge

And one for a standard shotgun shell with birdshot.

Note the addition of the “wad” that encircles the shot.  This is the plastic thing that you see fly out when you shoot a shotgun.

Cutaway of a Shotgun Shell
Cutaway of a Shotgun Shell

How Guns Work

Different types of guns have different mechanisms of how to ignite the primer to burn the gunpowder, but there is almost always a rounded metal object called the “firing pin” which strikes the primer and starts the process.

Below you can see that the firing pin is attached to a “hammer” in a revolver.

How a Revolver Works
How a Revolver Works

While in a rifle it could be by itself and held in a “bolt.”

Gas System Gun
Gas System Gun

Loading Mechanisms

Most guns will have a mechanism that gets rid of the spent casing and moves in a fresh cartridge.

Some of these include manual actions, using the recoil from the explosion, or using expended gas from the explosion.  We’ll go over these in detail in further lessons.  But for now, here’s some slow-motion of guns in action.

Additional Learning

Looking for a comprehensive handgun video course that only goes over the most important stuff…with none of the attitude?  Check out our very own Gun Noob to Gun Slinger course.

13 Leave a Reply

  • Dale Gribble

    I really feel like i should be paying for this info. THANK U SO MUCH!!

    6 months ago
  • geraldine quesenberry

    This was very interesting. Thank you for helping me understand what my gun is all about.

    1 year ago
  • Deepali Bangera

    Very well explained

    1 year ago
  • Conner Forbis

    Very well done. In-depth enough to remain informative but barebones enough to not be confusing. The diagram you added on an automatic rifle's gas blowback system was particularly good. It's as if you could imagine the gun firing and walking through the steps just looking at it.

    1 year ago
    • Eric Hung

      Thanks, Connor!

      1 year ago
  • Joy

    I'm a newbie and I like this! Thank you.

    1 year ago
  • cj pickup

    Hey GREAT website, but navigating through these "chapters" in the TUTORIALS, is kinda clunky. It would be nice if the chapter sections had a Next button to continue on at the end. (maybe even a Back button)

    1 year ago
  • Chris

    Im 15 and i'm really interested in guns and i'm glad I found this site it's a great learning experience.

    2 years ago
    • Eric Hung

      Thanks so much Chris!!

      1 year ago
  • FT Tern

    Your "cross section of a shotgun cartridge" isn't. :-/ It's a shotshell for use in a handgun.

    2 years ago
    • ehung

      Hi FT, you are correct. I've fixed it and thanks so much for catching it.

      2 years ago
  • Miguel Empeynado

    Good

    3 years ago
    • ehung

      Thanks!

      3 years ago
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