Hey Dig, I was always wondering what the "06" of 30-06 meant, thanks for clearing that up. Basically as was already stated, the common terms used for measuring bullet dimensions are often not their exact dimensions, although they're usually in the same ballpark. Another anomaly is the 8mm kurz (mauser) round which is actually 7.92mm. Also, some bullet sizes can come in all different lengths, eg "7.62mm" could mean 7.62x51mm (7.62NATO), 7.62x39mm (AK), 7.62x54R (Russian), 7.62x63mm, (30-06) etc. To further complicate things, 7.62x51/NATO can also be called .308cal. (If you're buying it commercially, it's probably going to be .308 unless it's military surpluss ammo) I think the point that I'm making is that you just need to know the terminology as the measurements aren't always exact, as was stated by others in the thread.