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.

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.

Short recoil is a firearm operating mechanism where the barrel and slide move together for a short distance after firing, then separate to complete extraction, ejection, and chambering.