Savage Arms during the Great War made Lewis guns for the Canadians (in .303), the Tsar of Russia (in 7.62x54R), and the U.S. Army & Navy (in .30-06), the latter in both M1917 (ground) and M1918 (air) variants.
In all, it was a thing of beauty as far as light machine guns went.
Image may be NSFW.
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Fold-out. Lewis Machine Gun 30-U.S. Government Airplane Model 1918, in Papers on Aeronautics. L’Aerophile Collection, Science, Business and Technology Division, Library of Congress