Caliber, a unit of length indicating a gun barrel's internal diameter or its length-to-diameter ratio, has played a crucial role in artillery design. Authors such as Ernest F. Henderson highlighted its tactical importance, explaining how it influences a weapon's performance, while "The Wonder Book of Knowledge" defined it as the measurement of the bore's diameter.
Thomas Wilhelm outlined specific calibers and their associated weights in military firearms, and the Warren Commission pointed out distinctions between inch and millimeter standards. Paul Severing demonstrated its technical influence, connecting caliber to projectile speed and armor-piercing capability. These diverse viewpoints illustrate how caliber has influenced both the practical aspects of gun engineering and the standardization of military specifications.