Hello Folks, this is somewhat useless knowledge but one way to tell the difference between the M1917 and the M1918 is the M1917 French piece has the serial number on the breech and the M1918 US made pieces have the number on the muzzle of the piece. I have this listed as a M1917A1 but I don't know that for a fact. About 40 around the US, these high speed conversions are pretty rare.