Re: Putting mil rad marks on reticle
Dave lets say you have a target that is 16".
You range the target and it is 4 moa. The math would be 16" divided by 4.188(the 4moa range reading x 1.047) equals 382 yards.
There is an easier way to do MOA. Since 1 moa is roughly 5 percent larger than 1 IPHY you can do the math like this: 16" divided by 4 = 400. Now subtract 5 yards for every 100 yards to make up for the extra 5 percent. So divide 400 by 100 which is 4. 4x5=20 So your finial range would be 400-20=380 yards. That is with in 2 yards of the correct reading and you can do this all in your head.
To figure in IPHY all you have to do is divide the target size by you actual reading without having to worry about that extra 5 percent. You don't have to convert anything because you are working with inches with your target size and your ranging scale.
Examples: 16" target, range reading 4 IPHY (16 divided by 4) 400 yards
2 IPHY(16 divided by 2) 800 yards
3 IPHY(16 divided by 3) 533 yards
With 1 mil being 3.6" at 100 yards its hard to do the math in my head and a mil is very course. The TMR, MLR and GEN2 mil reticles are better with their 1/2 mil spacing. I have one Leupold with the TMR reticle that I set a ruler up at an exact 100 yards and then I dialed the scope down until the 1 mil spacing read 4". I made a non permanent mark on the power ring where this was at. Then I went fine tuned it by shooting a 650 yard target that was taking 10 moa of dial up with a 100 yard zero. I then dialed the scope back to zero and used the 2 1/2 mil mark for a hold over aiming point. Then I used the power ring to adjust the point of impact. When I got to the same point of impact as the 10 moa dial up, I made a permanent mark on the power ring. With the 1/2 mil spacing of TMR adjusted to read 2 moa I have basically got the same reticle as the Nightforce NP-R2.
If I were to build a scope it would definitely have IPHY adjustments and a IPHY reticle. It's just easier for my simple mind.
I hope this helps.