by Apex Optics

We often get asked by recreational civilian shooters on how to use the elements of a MIL/MRAD reticle to determine the distance to a known-size target. This is a standard skill for military and law-enforcement snipers and designated marksmen, but it’s seldom taught in introductory or beginner-level long distance shooting courses. This concept is typically referred to as “MILLING” a target, and can be used to either determine the range of the target if you already know the size of said target, or conversely can be used to determine the size of the target if the distance is known.

This is a fairly simple exercise for someone with our TR2 reticle found in the Summit PRO binoculars, or using any one of our MIL riflescope reticles (i.e. CLR, HLR, HCR, etc.).

Firstly, we need to establish the concept of First vs. Second focal plane, and the scaling related to the zoom level. Most second focal plane (SFP) reticles are only useful for milling a target at maximum magnification, since the scale of the reticle is fixed and does not shrink or grow as you increase or decrease the magnification of the riflescope. This is why, for the most part, most long range shooters prefer to use first focal plane riflescopes (FFP) as the reticle is always properly scaled to the magnification of the optic, and the subtensions on the reticle are always accurately displayed. This, obviously, does not have any bearing on fixed power optics like binoculars.

Below is an example of our TR2 ranging reticle and the subtention values (i.e. line widths, and spacings). The minor value hashes are spaced 0.2 MILs from one another (center to center) from 0.2 to 10 MILs, 0.1 MIL from 10 to 11 MILs, and 0.5 MIL from 11 to 20 MILs.

Step 1

Use the reticle to determine the size of the target in MILs. Once you’ve done that, use one of the formulas below to determine the distance to the target.

Step 2

Using Centimeters for Target Size, and Meters for Distance

Here’s an example, a target is 25.4cm tall (10″), and the MILLED size is 1.5 MILs tall in your reticle. You would take the 25.4 and divide by 1.5, then multiply by 10. So your resulting math would look like 25.4/1.5 = 16.9333 * 10 = 169.333 meters

OTHER FORMULAS FOR YOUR REFERENCE

Using Inches for Target Size, and Yards for Distance

Using Inches for Target Size, and Meters for Distance

We will have a tutorial video with some real-world examples coming soon!