"30/06 basic brass, necked down and/or shortened is 9.3X62"
To clarify that a bit, the 9.3x62 was developed BEFORE the .30-06 round, in 1905, by Bock in Germany.
It was a completely new development designed to give German hunters a home-grown cartridge that would be capable of taking heavy African game.
In some European loadings it approaches 4,000 foot pounds of energy at the muzzle.
The .270 Winchester is also not based on the .30-06 case. It was developed from the older, longer, .30-03 case, and in fact matches that case's length exactly.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.