7.62 mm caliber is a nominal
caliber used for a number of different
cartridges. Historically, this class of cartridge was commonly known as
.30 caliber, the
Imperial unit equivalent, and was most commonly used for indicating a class of full power military main
battle rifle (MBR) cartridges. The measurement equals 0.30 inches or 3
decimal lines, written
.3" and read as
Three-Line.