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.

A type of semi-automatic pistol action where the barrel remains locked for a short period after firing, delaying the blowback of gases to slow the opening of the breech.

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