| Term |
Definition |
| Action |
Action is the term for the operating mechanism of a gun. It refers to the combination of moving parts that allow a shooter to load fire and unload a gun. |
| Adjustable Sights |
Sights that allow vertical (elevation) and horizontal (windage) adjustments. |
| Aperture |
The hole in a rear peep sight through which the shooter looks at the front sight and target. |
| Autoloading |
An action of semi-automatic or self-loading operations. |