If you extend the conversation, I think that we could infer that none of the currently "popular" metric cartridges would have much traction in the U.S. except for the infusion of cheap surplus military rifles post-WW1 and again post-WW2. The 6.5x55 would be a niche cartridge without all the surplus Swedish Mausers imported since the 1950s. The 7x57 would be the same if not for all of the surplus Centeral/South American Mausers, both small and large ring configurations. The 8x57 would also be the same if not for all of the war trophies and surplus German 88s and 98s.
The other day, I came across a 1961 vintage ad for the Hunters Lodge of Alexandria, VA, which appears to be related to Interarms, selling surplus British #1, #5, and Pattern 14 Enfields in 303, U.S. 1917 Enfields and 1903 Springfields in 30-06, German and Iranian/Persian Mausers in 8x57, South American and Spanish sr & lr Mausers in 7x57, Argentine 1891 Mausers in 7.65x53, Swedish 1894 (Interarms G33/40s) Carbines in 6.5x55, Italian Carcanos in 6.5x52, Russian Moisins in 7.62x54R, and French Lebels in 8mm Lebel. The prices ranged from $9.95 to $39.95. They also listed 3 different revolvers, Colt 1917s for $25, S&W Victorys for $35, and Webley & Scotts in 38 S&W for $17.
If not for WW1, Charles Newton's firearms production business might have succeeded and the 256 Newton might have become the standard American 6.5mm/.264" bore cartridge.
All relative, since hindsight is always 20/20.
JEff
