Letter: S

A form of firearm construction that has the firing mechanism mounted on detachable plates on the side.

A removable plate in the frame or receiver to allow access to internal parts or upon which some internal parts are mounted.

Any of a variety of devices, mechanical or optical, designed to assist in aiming a firearm.

The movement of a sight to change the point of impact.

The hole in the disc of an Aperture Sight.

That part of a sight that is usually attached to a gun.

The small cylindrical top portion on some forms of front sights.

1. (Front sight) An elongated projection usually mounted parallel to the bore, used as the front sight on some firearms. See Blade Sight. 2. (Rear sight) An elongated movable portion of an adjustable rear sight that incorporates the sighting notch or aperture.

Protective metal cover fastened about a sight to guard it from being moved out of adjustment from jars or blows. Sometimes called a Sight Hood or Hooded Sight.

That part of an aperture (peep) sight that contains the hole. May have either a fixed orifice or contain an iris diaphragm to vary its size.