The .30-06 Springfield cartridge (pronounced “thirty aught six”) is a .308 inch (7.82 mm)(.300 inch is 7.62mm) caliber rifle round, also known as the 7.62 × 63mm, introduced to the United States Army in 1906 (hence “-06”) and standardized, with use continuing into the 1960s, tapering off in the 1960s and early 1970s.