SLAVE PIN

A pin used during assembly of a firearm to facilitate the process and later replaced by a permanent pin or screw.

SLEEVE

1. A means of renewing old shotgun barrels by insertion of a tube into the bore or interior of the barrel. 2. A tube surrounding the receiver of a target rifle to improve rigidity. 3. The shot container in a shotshell. 4. The inner, rifled portion of a two-piece barrel.

SIDE-LOCK

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

SIDE-PLATE

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

SIGHT

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

SIGHT BASE

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

SIGHT BEAD

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

SIGHT BLADE

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.