Mils vs MOA, What is MOA, MOA rifles
Photo by David Bahde
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How did the mils vs MOA debate get started? We’ll get there. Before the advent of affordable rangefinders, range was determined using an instrument of measure, like the reticle in your optic. Given two “knowns” we can solve for the third (Algebra). The reticle provided one known, a mathematical scale. Given a known target size, you can then determine range. Some competitions require its use, and military units still practice it.

Mils vs MOA

Newer reticles can be used for holds (wind and elevation). Instead of dialing, you reference lines in the reticle—milliradians (mil) or minutes of angle (MOA). Good scopes are precise, even if you might not be. Using this method is fast and becoming popular in the military. Determine range, read the wind, hold in the scope and press the trigger. It works using this method out to 800 meters.

You can also make impact corrections using the scale in the reticle. Watch the impact holding the reticle in place. If you miss, identify where in the reticle, move that impact point to the target and press. There are more esoteric uses for sure, but these are the most common. You are determining range to target, using it to compensate for bullet drop and/or wind, and for follow-up shots.

Precision Marksman’s Mantra

Two scales dominate the market: Mils and MOA. What’s the difference? Simple, mils are metric, minutes of angle (as converted by most) are closer to inches, but not exactly. One mil is, well, one mil. It’s nothing more than a method of measurement, like millimeters and meters. One MOA is 1.047 inches at 100 yards. Push that out to 1,000 yards and 1 MOA is 10.47 inches. If you measure in yards and think in inches it is pretty handy. People accustomed to thinking in inches, yards and miles might prefer MOA, but the rest of the world thinks in millimeters, meters and kilometers. Both work just fine, and each has its advantages and disadvantages, depending on the user and use. 

Practical Application

Kahles USA was kind enough to provide a K624i scope using an MOAK reticle for comparison. The MOAK is configured in minutes of angle. Elevation and wind turrets use 0.25-MOA adjustments. Each click moves bullet impact 0.25 inches at 100 yards. My personal K624i uses an AMR reticle graduated in milliradians. Turrets are 0.10 mils, so each click measures 0.10 milliradian. Other than some overall upgrades to the new scope, they are identical. Mine sits on my Seekins Precision SP-10 build chambered in 6.5 Creedmoor. The MOAK K624i was mounted to a Primary Weapons MK212 in the same caliber, keeping the comparison close.

Zeroing

Zeroing is critical for most guns, incredibly critical for some. Finding that zero takes some effort, and both minutes and mils can be used effectively. Quarter-minute scopes change bullet impact 0.25 inches with each click of the dial (wind or elevation). Most mil scopes use 0.10 of a mil, equating to .39 inches at 100 yards. Assuming you, the rifle and ammunition always shoot within 0.25 inches, MOA is more precise. Most accomplished shooters can hold 0.5 inches at 100 with consistency, so 0.10 mils is fine for most. I was able to get both rifles dead center shooting sub-half-inch groups with ease.

Dialing Up

Most precision shooters use the knobs for elevation and wind adjustments. Mathematically, the MOA dials are more precise. It assumes the scope is precise (which both Kahles scopes were), along with the shooter. All things being equal, each click equates to less change as range increases, meaning an MOA dial allows more precision at range. That equates to more dialing to get that precision. Both rifles take about the same elevation correction at 1,000 yards—6.5 mils, or 23.4 MOA. It takes more turning with MOA knobs to get there. The Kahles MOAK has 35 MOA per revolution, more than most. Some will require multiple turns. That is really the only practical difference for most. Mils take less turns, MOA gets you some enhanced precision with more turns. 

Using the Reticle to Hold Elevation

Similarly to the dials, MOA scales are wider, meaning less in your field of view. You will hold higher on the scale (lower in the scope) given the same distance using an MOA scale. Mils will be much easier as the range extends, using less scale for elevation and wind. Holds are closer to the vertical center line using mils. You can use an MOA scale for holds, but there is a reason combat reticles designed for fast elevation and windage holds use mils. It’s just faster and easier. Yes, it’s slightly less precise, but if true precision is your need, the reticle is not the best tool. Use the dials. 

Ranging

The United States has been using mils for range measurement for years. Early scopes used mil dots or lines to range with MOA dials. It required a conversion, and Europeans looked at you like you were, well, stubborn Americans. But it works, and many still prefer it. These days, the best choice is matching your knobs and reticle. Pick one, and once chosen, commit to it. Don’t convert them back and forth. Simply put, a mil is a mil, not 0.39 inches—keep it simple. Either think in metric or inches, but avoid using both. 

Mils vs MOA, reticles
Mils (left) and MOA (right)

Depending on the reticle, both can be used to range with accuracy. The MOA scale is larger, meaning you might be limited at extended ranges. Using MOA allows you to think entirely in yards, though, and for some that is a huge asset. For most, the mil scale ranges well. Experts can range within 20 yards or less at some astounding distances, but it takes a ton of practice. If using a reticle for ranging at extended ranges (beyond 1,000 yards), you are going to want to use mils. For hunting or more close-range tasks, MOA works just fine. 

Other Considerations

One of the newest scales is IPHY (Inch Per Hundred Yards). To me, it’s nothing more than just dropping the 0.047 from the MOA equation. Throw it in a calculator and it’s more precise, just not something most use. It’s just a simplification of MOA that mimics the metric system. If that’s what you want, use mils—it’s easier and better supported. 

Both Kahles scopes use first-focal-plane reticles, meaning the reticle is accurate without regard to magnification. Second-focal-plane reticles are only accurate at one power—usually the highest, but not always. Your scope instructions should tell you. With practice, you can use SFP at other powers, you just need to use it and determine the differences. 

Few scopes are truly precise, and those that are cost more. Most are getting better, but never assume one click equals what it says on the dial. You must confirm by shooting your rifle and measuring the impacts. Use your reticle to measure known-sized targets to confirm accuracy. Shoot a target at a known distance using the knob, then the reticle. They should be the same. Check at various magnifications on an FFP reticle and at different ranges, as it might change. 

Bottom Line

Minutes and Mils are science, the application is an art. Both are tools. Use one, and you will gain proficiency. The world is full of instructors who can write a master’s theses on mils vs MOA with no clue how to use it. Application is key, not tedious study and mind numbingly boring class time. Learn how your scale works, then get on the range and use it. 

So what should you pick when it comes to mils vs MOA? Pick one scale, stick to it and use it. Eliminate conversions and think in one scale. There is no practical reason for conversions today. They only complicate what should be a simple process. If a scope requires a degree in math to use properly, we missed the point. It’s supposed to be about getting hits, not headaches. 

Keep it simple, use what works best for you, and above all practice, practice, practice! For more information, visit Kahles.at/us.

This article is from the Ballistic Precision 2020. Print and digital copies available at OutdoorGroupStore.com.

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