So, shall I call it Model 1917 or P17?
I suspect we have have what in the US we call Purists. They believe it has to be exactly as it was noted (US Rifle, Caliber .30, Model of 1917) and hell will fall on your head if you don't.

Ferris who wrote the definitive book on the 1917 thought so. He did an incredible job (its worth buying)

I don't agree. Interesting and love for the gun is what counts.

So, P17 is fine

1917 is fine (there are other 1917 model US equipment items so it can be confusing.

1917 Enfield is fine (and was used in one of the US manuals on the gun!)

30-06 Enfield and a host of other slang terms.

Model of 1917 is fine.