Much as I like O'connor, his comment that the 7x57 was the daddy of the '06 sounds like pure BS & writers' tales of mystery & imagination.
Though I'm not a historian, the only thing the 7x57 & the '06 have in common is that they are both bottleneck cases, rimless & share the same casehead diameter............same as lots if others.
MM
I guess Jim Carmichel was full of BS too. "America didn't catch up with the 7mm for 14 years, with the final development of the 30/06 in 1906. In fact, were it not for the 7mm Mauser, America's favorite son, the 30/06, might never have been created because the 7mm was the spiritual and physical father of the '06." March 1984 Outdoor Life
Perhaps JB or others could weigh in on the interpretation of the statements of these two men.
"America didn't catch up with the 7mm for 14 years, with the final development of the 30/06 in 1906. In fact, were it not for the 7mm Mauser, America's favorite son, the 30/06, might never have been created because the 7mm was the spiritual and physical father of the '06." March 1984 Outdoor Life