What is a gauge and what is its difference between a caliber?
Gauges and calibers are measures of the diameter of shotgun shells or rifle bullets. Although they measure the same thing, they use two different systems. Calibers, used in rifles and handguns measure the diameter of the bullet in either the metric or English system. Examples include the 5.56mm (.223 Winchester) round used my the American military in the M16 rifle or the 9mm round used in the military’s M9 or M11 sidearm. Shotguns on the other hand, are measured in a completely different way. The gauge, for example 12 gauge, is the amount of lead balls of the diameter of the shell needed to equal one pound. For 12 gauge, that means that 12 lead balls of a .729 inch diameter would be needed to equal one pound. Since the smaller the diameter of the barrel, the greater number of lead balls are needed to make a pound of lead, the greater the gauge, the smaller the diameter of the shell. Below are the conversions of gauge to actual diameter: 10 gauge = .775 inch 12 gauge = .729 inch 16 gaug
