sabot: a device used in a firearm to fire a projectile, such as a bullet, that is smaller than the bore diameter.
safety: A mechanism used to help prevent the accidental discharge of a firearm, helping to ensure safer handling. Safeties can generally be divided into sub-types such as internal safeties (which typically do not receive input from the user) and external safeties (which typically allow the user to give input, for example, toggling a lever from "on" to "off" or something similar). Sometimes these are called "passive" and "active" safeties (or "automatic" and "manual"), respectively.
|sawed-off shotgun/short-barreled shotgun|
selective fire: A firearm that fires semi–automatically and at least one automatic mode by means of a selector depending on the weapon's design. Some selective fire weapons utilize burst fire mechanisms to limit the maximum or total number of shots fired automatically in this mode. The most common limits are two or three rounds per pull of the trigger.
semi-wadcutter: A type of all-purpose bullet commonly used in revolvers that combines features of the wadcutter target bullet and traditional round nosed revolver bullets, and is used in both revolver and pistol cartridges for hunting, target shooting, and plinking. The basic SWC design consists of a roughly conical nose, truncated with a flat point, sitting on a cylinder. The flat nose punches a clean hole in the target, rather than tearing it like a round nose bullet would, and the sharp shoulder enlarges the hole neatly, allowing easy and accurate scoring of the target. The SWC design offers better external ballistics than the wadcutter, as its conical nose produces less drag than the flat cylinder.
shooting range: a specialized facility designed for firearms practice.
short-barreled rifle: a legal designation in the United States, referring to a shoulder-fired, rifled firearm with a barrel length of less than 16" (40.6 cm) or overall length of less than 26" (66.0 cm).
sleeving: A method of using new tubes to replace a worn-out gun barrel.
slide bite or Snake bite: A phenomenon often grouped with hammer bite—in this case the web of the shooting hand is cut or abraded by the rearward motion of the semi-automatic pistol's slide, not by the gun's hammer. This most often occurs with small pistols like the Walther PPK and Walther TPH that have an abbreviated grip tang. This problem is exacerbated by the sharp machining found on many firearms.
snubnosed revolver: a revolver with a short barrel length.