Which term describes the mechanism for firing a shot in a firearm?

The term that describes the mechanism for firing a shot in a firearm is "action." The action encompasses the entire system that loads, fires, and ejects cartridges in a firearm. It includes the components that facilitate the cycling of ammunition, allowing the shooter to fire multiple rounds.

Different types of actions exist, such as bolt-action, semi-automatic, and pump-action, each involving unique mechanisms for firing. Understanding the action of a firearm is crucial for safe handling and operation, as it directly influences how the firearm performs during use.

The other terms have specific meanings in the context of firearms but do not accurately represent the complete mechanism for firing. The trigger is a component that activates the firing process but does not encompass the entire mechanism, while the chamber refers to the part of the firearm where the cartridge is held before firing. Breach, or more commonly spelled "breech," refers to the rear part of the barrel where the cartridge is inserted; it is a key aspect of the action but not the overall mechanical process to fire a shot.