How a Firearm Works

The same physical process is used to shoot shotshells from shotguns or cartridges from rifles or handguns. Pulling the trigger causes the firing pin to strike and explode the primer in the base of the cartridge or shotshell. The spark from the primer ignites the gunpowder, which burns rapidly and converts to a gas. The gas rapidly expands and drives the projectile(s) through the barrel with great force.

How the rifle and handgun fire:

1. A cartridge is inserted into the chamber.
2. The action is closed, and the firing pin is pushed back and held back under spring tension.
3. The trigger is squeezed, releasing the firing pin, which moves forward with great force. The firing pin strikes the primer, causing it to explode.
4. The spark from the primer ignites the gunpowder. Gas converted from the burning powder rapidly expands in the cartridge.
5. The expanding gas forces the bullet out of the cartridge and down the barrel with great speed.
6. The rifling in the barrel (see Differences Between Rifles, Shotguns and Handguns) causes the bullet to spin as it travels out of the barrel. The bullet's speed and escaping gases produce a "bang."

How the shotgun shoots:

1. A shotshell is inserted into the chamber.
2. Closing the action pushes the firing pin back and holds it under spring tension.
3. Pulling the trigger releases the firing pin. The firing pin strikes the primer producing sparks.
4. Heat and sparks from the primer ignite the gunpowder. Gas converted from the burning powder expands in the shell.
5. The expanding gas forces the wad and shot out of the plastic body of the shell.
6. The escaping gases produce a “bang” as the wad and shot leave the barrel.
7. The wad quickly opens and falls away. The shot cluster spreads. This spread is called the shot string.