The October issue of the American Rifleman has an article by Bruce Canfield on American firearms of the Punitive Expedition.
Most of the information contained in the article will not be new to anyone here, but it is interesting. One thing that I didn't know, however, is that some .303 Lewis Guns were purchased in this time frame and used by the Army in Mexico.
Overall, it's nice article on American small arms of the 1916 period. Hardly exhaustive, but nicely done.