Firearm action

In firearms terminology, an action is the mechanism that handles the ammunition (loads, locks, fires, and extracts the cartridges) or the method by which that mechanism works. Breech-loading weapons have actions; actions are technically not present on muzzleloaders, as all loading is done by hand. The mechanism that fires a muzzle-loader is called the lock.

Actions can be categorized in several ways, including single action versus double action, break action versus bolt action, and others.

Manual operation is a firearms term describing any type of firearm action that is loaded one shot at a time by the user rather than automatically. For example, break action is a form of manual operation using a simple hinge mechanism that is manually unlatched by the operator, exposing the chamber(s) for reloading.

These are actions wherein the breechblock lowers or "drops" into the receiver to open the breech, usually actuated by an underlever. There are two principal types of dropping block: the tilting block and the falling block.

In a tilting or pivoting block action, the breechblock is hinged on a pin mounted at the rear. When the lever is operated, the block tilts down and forward, exposing the chamber. The best-known pivoting block designs are the Peabody, the Peabody–Martini, and Ballard actions.

The original Peabody rifles, manufactured by the Providence Tool Company, used a manually cocked side-hammer. Swiss gunsmith Friedrich Martini developed a pivoting block action by modifying the Peabody, that incorporated a hammerless striker which was cocked by the operating lever with the same single, efficient motion that also pivoted the block. The 1871 Martini–Henry which replaced the "trapdoor" Snider–Enfield was the standard British Army rifle of the later Victorian era, and the Martini was also a popular action for civilian rifles.

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