Good Lord! Nationalism had nothing to do with the adoption of the 1903 over the Brit-designed P-14. The US National Armory in Springfield, Massachusetts was tooled for the 1903 Springfield, the other guns needed to be purchased on contract with private makers such as Winchester and Remington. In the peace time between the wars the Armory kept up fine. In my opinion, the 1903 is a much smoother action than the P-14/17. The ejector was tougher, and the cocking easier. It was less bulky. But that aside, the last thing the post war US Government needed was to be buying guns from private manufacturers while probably paying yet another royalty, this time to the Brits, for a US made rifle.... As they did with the Norwegian designed Krag, and the Springfield 1903 which was a deemed a patent infringement on the German Mauser.
Come on Kev. If it was "nationalism" that drove them they'd be shooting the Remington Rollingblock, a Winchester lever gun, or a Trapdoor Springfield 45-70 at the onset of WWI. I don't know why you persist in this line of thought.~Muir