A cartridge is inserted into the chamber. The action is closed, and the firing pin is held back under spring tension.
When the trigger is squeezed, the hammer falls and hits the firing pin. The firing pin moves forward with great force, striking and igniting the primer in the cartridge base.
The spark from the primer ignites the gunpowder, generating gas pressure. The pressure from the expanding gas forces the bullet forward and out of the barrel. The bullet’s speed and escaping gases produce a “bang.”