Something like the Winchester M1907 would probably be more likely, then. It was in French use by 1915, British some time around 1914, and Russian by 1916. Late war developments saw the Winchester Machine Rifle developed, which used the same round as the M1907 but with a spitzer projectile, and the 8mm French assault rifle whose name I can never remember. Ribolloye or something similar.
Other interwar intermediates tended to range from 7-9mm in diameter, so such a tiny round as the .220 Swift probably wouldn't be considered by the military of the time.








