Guns, Firearms, Projectile Weapon Sports/gun mechanics


I am an author with no experience with Firearms.  Can you explain to me in layman's terms what happens inside a handgun when it is fired? (Let's just assume a semi-automatic.)  I need to understand the mechanics and physics (at least the simple person's version) for a novel that I am working on. Thanks

I started a Gun and Tactics youtube channel where I address a lot of gun issues. Here are links:

Not sure how simple it will be but I will give a shot.

A cartridge is a brass casing that holds the primer in the back, then gun power, then the lead bullet at the end.  A primer is a small enclosed explosive, like a cap, that pops and throws out flame or sparks, those sparks ignite the gun powder, the power explodes and forces or blows the bullet down the barrel at the target.

A gun is a mechanical device in it's simpliest form which has a barrel at the rear of the barrel is a chamber and the holds the bullet straight and tight and in the same spot so when the bullet is fired it will go down the barrel straight. Inside the barrel is what is called rifling, this is basis grooves the spiral along the inside of the barrel to make the bullet spin has it goes down the barrel. That spinning action helps the bullet fly straight and level.  The old black powder guns did not have this so their bullets were just round and were not very accurate.

Once you put a bullet/cartridge in the chamber or barrel another piece normally called the bolt pushed up against and locks the bullet in the chamber. Inside the bolt is a spring and firing pin.

The firing pin punches the primer of the bullet causing the round to go off.

The firing pin is normally locked back with a safety and is not released until the safety is off and the trigger is pulled.

Pulling the trigger, release a spring that pushes the fining pin, that hits the primer that sparks the gun powder, that explodes inside the casing forcing the bullet down the barrel where the rifling spins the bullet as it leaves the gun and if you aimed it right you hit your target.

So, did I confuse you?

here is a video that shows a semi auto pistol being fired. What you will see very fast is the person squeezes the trigger with his finger, the hammer springs forward and strikes the rear of the firing pin, the pin is pushed into the bullet, the bullet fires, the force of the bullet forces the slide, the top of the pistol back, that action re cocks the hammer, kicks out the empty fired round and then when it moves forward it loads another live round and the things repeats.

Guns, Firearms, Projectile Weapon Sports

All Answers

Answers by Expert:

Ask Experts


Rick Gore


I have a Gun & Tactics YouTube channel where I address a lot of gun issues. Here are links: All About Guns & Tactics . All About Guns Police & Military Tactics . I can answer most general questions about handguns (no value or history). Firearms Instructor for over 30 years. Specific knowledge on Glock and Colt 1911s models. -----------------------NO VALUE OR HISTORY QUESTIONS----------------NO REFERRALS--------- -- **---I have to do this since I keep getting value and history questions---**


I have been firearms trainer/instructor in the Air Force, Civilian Law Enforcement, NRA Pistol Instructor and the FBI. I am a Armorer for 1911s and Glock firearms. I started a Gun and Tactics youtube channel where I address a lot of gun issues. Here are links:

Certified Instructor and Armorer All About Guns .

©2017 All rights reserved.