M&P Dawson Precision Sight mathmatics

[Alfie]

Is there a rule of thumb for changing the height of the front sight to adjust the point of impact at a certain range, say 25 yards?

I want the pistol to shoot about 5 inches lower then it does now with the same point of aim. I'll need to install a taller front sight but which one? Right now I'm using a .160 DP optic front.

[High Lord Gomer]

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.

[Darrin]

9L is 7.125

[Alfie]

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.

And it's answers like this that make me ask the questions. Thanks!!!

I was refering to a 9/40 and not the L or Pro. So if I'm using a .160 now and I want to add 0.035556 then I need 0.193 or 0.190 from the Dawson Catalog. Sweet!

[High Lord Gomer]

I tried measuring the true sight radius on one of mine but my digital calipers only go to 6". If you have other than factory sights, or if you doubt the exact accuracy of the published number, you need to measure the distance from the top rear surface of the rear sight to the top rear surface of the front sight to get the exact number to place in the equation: x * 5 / 900