Starline Unprimed Brass Cases 308 Win (50pk)A. K. A . 308 Winchester, . 308, 7. 62mm Nato, 7. 62x51mm2. 002 2. 009 O. A. L. The venerable . 308 Winchester has made quite a name for itself since it was first introduced in 1952. The . 308 and its military equivalent, the 7. 62x51mm Nato, is a very efficient cartridge that has excellent ballistics, while still being fairly easy on the shoulder. That, and its inherent accuracy have kept it thriving as both a competition and hunting calibre.