A firearm feed system where ammunition is stored in a flexible or rigid container (magazine) inserted into the grip or attached externally, feeding rounds into the chamber via a spring or follower.

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

A mounting system for attaching optical sights to rifles.

Firearm action type where the energy from firing a cartridge cycles the action via rearward movement of the barrel or slide.