P14/P17 lower and upper handguard.

[Mk VII]

Flying10uk-- I am surprised that the British purchasing commission would let them get away with that. US Ordnance insisted on a commonality of parts for the M1917.

--fjruple

We should remember that the British were dealing with each factory on a commercial basis and there was no incentive for each facility to ensure interchangeability or cooperation or revelation of trade secrets. The British thought they needed the guns a lot more than the manufacturers needed their business (and indeed Winchester ended up making a loss on their British contracts, which made them reluctant to treat with Britain again in the next war.)

Once Uncle Sam was paying the bills they were forced to start paying closer attention to interchangeability. But it remained problematic.
C.S. Ferris's United States Rifle Model of 1917 shows photos of Winchester and Remington front h/g's with the different length of the metal clip and the placement of the rivets.