Assuming the published sight radius of 6.4" for the M&P9/40 is correct, if you want to make a change of 5" at 25 yards, that is 5" at 900", so to make the same change at only 6.4"...
6.4 (sight radius) * 5 (change at 900") / 900 = .035556"
I did a quick check and didn't see a sight radius published for the 9L / Pro.