Firearm mechanism where the barrel and breech pivot open for loading/unloading, typically via a hinge at the frame.

Adjustable metal aiming devices on firearms, consisting of a front post and rear notch, used without magnification.

Rimfire: a type of ammunition in which the primer is located in the rim of the cartridge case and is ignited by the firing pin striking the rim.

A firearm feed system where only one round is chambered and fired per cycle, requiring manual reloading.