OK...my buddy who was in the Marine Corps. for several years, says that the Marines taught him that you can shoot the ammo you use in an M16 (5.56NATO or .223) in an AK47 (7.62x39). I told him that is BS. I say the .223 round will go BOOM in an AK47 chamber. He swears up and down that it was drilled into his head for three weeks that you can shoot the same ammo in an M16 and AK47. What the hell is he talking about?