A firearm feed system where ammunition is stored in a separate container (magazine) that can be removed and replaced, enabling rapid reloading.

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.

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.

A pistol barrel with external helical grooves allowing the attachment of a suppressor or other muzzle devices.