Hi Rule303,

Sorry for this rather off topic.
I must disagree about the statement "...US studied the 8X57 and used it's dimensions but lengthened for greater powder capacity and hence greater velocity."

At that times, the 30-03/30-06 size was a mistake, a waste of material, and innecesarily large capacity. With the powders available then, the 8x57 and, specially, the 7,65x53 (the first truly Mauser designed cartridge), were a lot more efficient and rational designs.
The 30-06 never achieved the ballistic efficiency and performance of the German military 8x57 IS. Or the 7,65x53 one, by the way.

Today, with the actual powders, the thing is, somewhat, different of course!

Best regards

PH