I have a Remington made M1917 in very good condition. I am designing a compact rear sight for it which can be easily adjusted for windage and elevation. I won't alter the rifle other than removing the military sight and attaching mine.
One point for attachment is the hole for the screw that retains the rear sight spring. On page 88 of my copy of Charles Stratton's book, he says the screw is .14" diameter and 37 threads per inch. The M1917 and P-14 use the same screw.
Can someone explain where this weird screw thread came from? Could this be a mis-identified 6-40 thread?
I was able to twist a 6-40 bottoming tap into the hole all the way to the bottom using fingers only with no resistance.