Given the heavy recoil of the .30/03 with it's 220 grain bullet on soldiers using Model 1903 Springfield rifles the Army would have been wise to have simply adopted the 175 grain 7mm Mauser cartridge.
Only after the Army loaded it's then new thirty calibre cartridge with 150 grain bullets did the recoil became tolerable for the troops. That birthed the 30/06.
I bet that if we had adopted the 7mm Mauser cartridge there would have been no need for the 7.62 NATO or 5.56 NATO. We might still be using the 7x57mm in some loading as our standard rifle and machine gun round. Even after over a hundred years!
