5 results about "Caliber" patented technology

In guns, particularly firearms, caliber (or calibre in British English) is the specified nominal internal diameter of the gun barrel bore regardless of how or where the bore is measured and whether or not the finished bore matches that specification. It is measured in inches to an accuracy of hundredths or thousandths of an inch or in millimeters. For example, a ".45 caliber" firearm has a barrel diameter of roughly 0.45 inches (11 mm). Barrel diameters can also be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Due to the inaccuracy and imprecision of imperial dimensions "converted" to metric units, metric designations are typically far out of specifications published in decimal inches. True "caliber" specifications require imperial measure, and even when cartridge designations (often mistakenly referred to as "caliber") only specify caliber to even tenths or hundredths of an inch, actual barrel/chamber/projectile dimensions are published to at least thousandths of an inch and frequently tolerances extend into ten-thousandths of an inch.