.30 caliber, rimless bottleneck rifle cartridge (Springfield)

.30 is the (approximate) diameter of the rifle bore for the caliber cited (in inches). -06 refers to the year the cartridge was adopted by the military.

The .30-06 cartridge was developed for the military and came into service in 1906. It was used in the primary infantry rifles from World War 1 through the Korean war and in .30 caliber machine guns into the 1970’s. It was replaced by the NATO standard 7.62x51mm cartridge.

Due to its excellent ballistics, the .30-06 cartridge was adopted by sport shooters soon after its introduction for hunting and target shooting and is still used for those purposes today.