firearm

A firearm is a device that uses rapidly expanding gases produced by the ignition of propellant in a cartridge to propel a projectile through a barrel. Modern firearms are typically hand-held or shoulder-fired weapons used for military, law enforcement, sporting, and hunting applications. A firearm generally consists of a frame or receiver, a barrel, an action that loads and fires ammunition, a stock or grip, a trigger mechanism, and sights. Ammunition is a cartridge containing a primer, propellant, and a projectile.

Firearms operate through various mechanisms and action types. Firing typically involves a controlled ignition of the primer, generating gas pressure that drives the projectile down the bore. Actions can be manual (bolt-action, lever-action, pump-action), semi-automatic, or fully automatic. Magazines or belts feed cartridges into the firearm, depending on design. Common categories include handguns (revolvers, semi-automatic pistols), rifles (bolt-action, semi-automatic, lever-action), and shotguns.

The development of firearms began in the medieval period with gunpowder weapons and evolved through percussion locks and breech-loading designs. The late 19th and 20th centuries saw rapid adoption of automatic and semi-automatic systems, enhancing rate of fire and reliability.

Use and regulation vary widely. Firearms are used for defense, sport shooting, hunting, and professional duties, but their possession and deployment are subject to legal controls that differ by country and region. Safety emphasis includes treating all firearms as loaded, keeping the muzzle directed away from others, keeping the finger off the trigger until ready to fire, and secure storage. Regular maintenance such as cleaning and inspection is essential to reliable operation.