Caliber

Caliber Cal"i*ber, Calibre Cal"ibre, n. [F. calibre, perh. fr. L. qualibra of what pound, of what weight; hence, of what size, applied first to a ball or bullet; cf. also Ar. q[=a]lib model, mold. Cf. {Calipers}, {Calivere}.] [1913 Webster] 1. (Gunnery) The diameter of the bore, as a cannon or other firearm, or of any tube; or the weight or size of the projectile which a firearm will carry; as, an 8 inch gun, a 12-pounder, a 44 caliber. [1913 Webster]

The caliber of empty tubes. --Reid. [1913 Webster]

A battery composed of three guns of small caliber. --Prescott. [1913 Webster]

Note: The caliber of firearms is expressed in various ways. Cannon are often designated by the weight of a solid spherical shot that will fit the bore; as, a 12-pounder; pieces of ordnance that project shell or hollow shot are designated by the diameter of their bore; as, a 12 inch mortar or a 14 inch shell gun; small arms are designated by hundredths of an inch expressed decimally; as, a rifle of .44 inch caliber. [1913 Webster]

2. The diameter of round or cylindrical body, as of a bullet or column. [1913 Webster]

3. Fig.: Capacity or compass of mind. --Burke. [1913 Webster]

{Caliber compasses}. See {Calipers}.

{Caliber rule}, a gunner's calipers, an instrument having two scales arranged to determine a ball's weight from its diameter, and conversely.

{A ship's caliber}, the weight of her armament. [1913 Webster]