Hi coolbrze0,
The " 06" stands for the year the .30-06 was adopted for military service, 1906. The caliber is actually .308 which is the same as a .30-30 and most other .30 calibers. (In .30-30 the first 30 stands for caliber, the second thirty represented the charge weight in black powder for the original load.....30 grains.)
ak, you are right about the nomenclature in which the last 30 stands for the weight of the powder, BUT the .30/30 was NEVER loaded with black powder. Neither was the .30/40 Krag, but the .303 British was!!