Originally Posted by JP@AK

Guy is correct. Somewhere in the 1917-1919 period is a good approximation. You didn't show the left side, so we can't see whether the monogram is present. That might help us narrow down the possibilities. It would take a records search to be certain in any case.

If you look at the patent dates on the top of the barrel, you will notice the last one is December 29, 1914. That indicates the Fourth Change, which first appeared in 1915.

The nickel finish appears to be original, and so do the stocks. A nicely preserved piece. Enjoy it.