It's not a ".308", but....it is. A 7.62x39 is in the range of .30 cal, same as .308 Win, .30-30, .30-06, etc. It's all about the same diameter, but of course the cartridge length, shape of the bullet, and powder charge are all different. That's why you can't just stick any ".30 caliber" bullet in the chamber of any ".30 caliber" gun. If you have an AK chambered for 7.62x39, you NEED 7.62x39. Don't buy .308 for it.