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.

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

Uses high-pressure gas to cycle the action, rather than recoil energy.

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