You’ve heard of them, maybe even looked through a scope with one, or even used one, but what is a Mil-Dot reticle in your rifle scope? For those not familiar with the Mil-Dot reticle, they offer many advantages. The military uses Mil-Dot reticles to allow range estimations in the field. Obviously, laser range finders are better, but it’s another piece of gear to carry along and laser range finders require batteries.
The basic Mil-Dot reticle uses a series of dots along the crosshairs of the scope. These dots have a defined relationship useful for estimating the range once you understand how to use them.
Let’s define MOA “minute of angle.” There are 360 degrees in a circle. When we divide one degree into 60 parts, we have an MOA. Since 100 yards is a common range for sighting in a rifle, talk commonly turns to how a rifle will group at 100 yards. Can a rifle shoot MOA groups? This means that the rifle can keep the group an inch or less at 100 yards. MOA groups are often referenced.
In actual fact, a 1-MOA at 100 yards is 1.047 inches with the assumption that an inch is good enough (virtually no one can hold tighter than 0.047 of an inch anyway). This is found by multiplying the range by the sine of the angle. Using the range in inches (100 yards = 3,600 inches) times the sine of 1/60 of a degree (1-MOA) gives us the 1.047 inches at 100 yards. This is easy to find with a scientific calculator.
If 1-MOA is a bit over an inch at 100 yards, how large is 1-Mil at 100 yards? Let’s define a Mil. Some think that “mil” comes from “military,” but that is not the case.
You’ve heard of them, maybe even looked through a scope with one, or even used…
by Paul Markel / Aug 17, 2009