How does an automatic weapon work?

With the advent of machinery in the 18th century, inventors were able to mechanize the process of shooting--allowing semi-automatic & automatic weapons to be developed.

Most automatic weapons have the following cycle:

1- Firing (firing pin strikes primer, propellant burns forcing projectile down the barrel),

2- Extraction (spent brass casing is extracted from the chamber),

3- Ejection (spent brass casing is ejected clear of the weapon),

4- Chambering (a fresh round is fed into the weapon's chamber)

The weapon cycles automatically. If only one bullet is fired per every pull of the trigger, the weapon is said to be semi-automatic. If more than one bullet is fired with every pull of the trigger, it is considered automatic.