A bayonet lug is a metal fitting on the barrel or muzzle of a firearm that provides a mounting point for a bayonet.

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.

Integral bipod: a permanently attached, built‑in bipod that provides a two‑point support for a firearm, allowing it to be rested on a surface without separate accessories.

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

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

Select fire is a fire selector mechanism on a firearm that lets the shooter choose the firing mode, such as semi‑automatic, burst, or fully automatic.