Well, ".30-06" doesn't have "springfield" in it's name, and ".30-06 springfield" does[&:]...all kidding aside, the guys above have got it right, they're exactly the same thing, ".30-06Springfield" is what SAAMI refers to it as, ".30-06" is what Bubba refers to it as....the biggest thing about the nomenclature that I feel is important is the fact that there are a few different ".30-06's" available, i.e. the "Springfield" and the "Ackley Improved", and a few other wildcats hanging around out there that don't offer any real improvement but feed on the fact that they're "better, newer cartridges, but based on a Classic design"....but whenever someone says they run a .30-06, you can be 99.99% certain that they're talking about a Springfield.