Firearm
Automatic

Automatic is a firearm action that uses the same automated action cycling as semi-automatic, but continues to do so for as long as the trigger is actuated, until the trigger is let go of or the firearm is depleted of available ammunition. The excess energy released from a discharged cartridge is used to load a new cartridge into the chamber, then igniting the propellant and discharging said new cartridge by delivering a hammer or striker impact on the primer. Automatic firearms are further defined by the type of cycling principles used, such as recoil operation (uses energy from the recoil to cycle the action), blowback (uses energy from the cartridge case as it is pushed by expanding gas), blow forward (use propellant gas pressure to open the breech), or gas operation (uses high-pressure gas from a fired cartridge to dispose of the spent case and load a new cartridge).
oulipo:avoid_letter[a], combination:repeat_prompt