semiautomatics

Semiautomatics are devices that perform an automatic action to prepare for the next operation after each use, but still require a separate input to initiate the sequence again. In common usage, the term refers most often to semiautomatic firearms, which fire one round per trigger pull and automatically prepare the next round for firing.

In firearms, a semiautomatic weapon uses the energy from firing to cycle the action: the spent cartridge is ejected, the bolt or slide chambers a fresh round from the magazine, and the firearm remains ready to fire again with the next trigger squeeze. This contrasts with fully automatic firearms, which continue firing as long as the trigger is held down. Semiautomatic systems are found in pistols, rifles, and some shotguns, and they rely on various mechanisms such as gas-operated or recoil-operated actions.

Semiautomatic designs emerged in the late 19th and early 20th centuries and later became widespread in military, law enforcement, and civilian use due to their balance of rate of fire and controllability. Notable examples include early service pistols and later models from major manufacturers, as well as contemporary platforms used for sport and defense. In many rifle platforms, the term distinguishes semiautomatic variants from fully automatic models that exist in limited capacities in some regions.

Legal status for semiautomatic firearms varies by jurisdiction, with regulation often affecting ownership, magazine capacity, and transfer. Safety considerations emphasize proper handling, secure storage, and compliance with local laws. Outside firearms, the term semiautomatic can describe other mechanisms that automatically prepare the next cycle after a user action, though its most common association remains firearms.