Mils versus MOA Explained
One question we (often sheepishly) get asked all the time at XRO is “should I get a mil or MOA scope?”, so today we’re gonna tackle the ins and outs of the topic so you can use your precision gear to its maximum potential. We’re going to center the discussion here around the topic of long range precision scopes specifically, since that’s what 99% of the topic revolves around.
For starters, we need to understand- what’s the difference between Mils and MOA? Both are units of measuring angle, with mils being a metric-based measurement system and MOA being essentially an Imperial system. Now the terms “mil” or MRAD are abbreviations for a “milliradian”, which equates to the angle of exactly one meter at 1000 meters- that is to say, if you adjust your scope’s turrets one full mil, you’d move your point of impact one meter at 1000 meters.
Changing gears to MOA now- MOA stands for “Minute Of Angle” which equates to almost exactly one inch at 100 yards (technically 1.047” at 100 yards, but we’ll round to 1” for brevity here), once again meaning that if you adjust your scope by one full MOA, you’ll move your point of impact by one inch on your 100 yard target. See, both systems of measure serve the same purpose, but in different units- meters/centimeters and inches/feet/yards.
Clear as mud? Good, let’s dig deeper.
So, what are the advantages of mils versus MOA? Well, that depends on the situation, but in a nutshell- using mil-based reticles and turrets can help save you some time doing math in the field, and for those like myself who didn’t exactly relish the subject in high school, that’s a huge advantage. Since the MRAD/mil system is based off of meters, everything in it is based on multiples of 10. Most mil scope turrets are set up to adjust in 0.1 mil increments- so one “click” is one tenth of a mil (which handily works out to one centimeter at 100 meters). The beauty of this system is that as long as you know the rough size of your target in meters, you can easily figure precisely how much you’re moving your point of impact between shots, and you can even use a mildot or other mil-based reticle to range the distance to your target! Now you can of course do that same thing using an MOA scope as well, but because MOA scopes work in inches/feet/yards, all your distance and size calculations now have to be done in multiples of 4’s, 12’s, 24’s, and 36’s… which wreaks havoc on my already-stunted math skills. Your mileage may vary of course.
Another trickier question we get a lot is this: “which is more precise, mils or MOA?”. Neither system is technically more precise than the other on a mechanical level, however most MOA scopes feature ¼ MOA adjustment per “click” as opposed to most mil scopes which will have 0.1 mil adjustments per click. Now with our handy knowledge from above on the way the systems work, we know that a ¼ MOA scope adjustment would move your point of impact only ¼ of an inch on a 100 yard target, while a 0.1 mil adjustment on a target at 100 meters would move point of impact a full centimeter. For this reason, MOA scopes generally offer finer adjustment, making it possible to “dial in” your shots to a finer degree. But before we declare MOA the winner on those grounds, we should consider just how much of a difference that really makes in the real world- even at 1000 yards, the difference in size between 0.1 mil and ¼ MOA on target is only about 1.5”… and if that’s enough to make you miss at 1000 yards, you’re a far better shot than I!
Now, the above paragraph may be generalizing things quite a bit, as there are plenty of other adjustment types under the sun, however ¼ MOA and 0.1 mil have risen to the top as the “gold standards” over the past few decades. A lot of older American scopes may have adjustments in ½ or even just 1 MOA increments, while many “target” scopes have even finer 1/8th or 1/10th MOA clicks. Many European hunting scopes have adjustment in weird increments like “7mm per click at 100m” or the like. Now, recently there’s been a trend towards fine adjustments or splitable adjustments in both the mil and MOA fields which will hopefully continue, but at least for the time being my point above stands- MOA scopes do generally offer finer adjustment.
So, which should you get- mil or MOA? My standard recommendation is that new long range shooters or anyone who already uses the metric system naturally will be best served with a mil-based scope if possible, as it will be more natural to use and will keep you from having to do additional conversions in your head. Now, if you’re the type who’s been using MOA for years already and you’re familiar and fast with it, I suggest sticking with what you know, and here’s why- I was an MOA shooter for years! I was quick with it, and it felt natural, but eventually the MRAD craze came over me and I decided to liquidate my MOA optics in favor of mils. In the end, it did make me faster at doing range calculations and drop/drift adjustment, however trying to get my brain to think in meters instead of yards was a 2-3 year process of re-learning judging distance. In the end, it took a lot of mistakes to gain back the proficiency I previously had. There’s definitely something to be said for the “if it ain’t broke, don’t fix it” mentality.
At the end of the day, to maximize precision and minimize your down time, I always suggest you go for whatever feels more natural to you, and then stick with it. Choose a reputable optic brand and model, mount it in good rings/bases, remember your fundamentals, and practice practice practice! The worst thing you can do is try to mix the two systems (looking at you here, US military)…
And as for me? Well I can now finally say I am fully recovered, a true mil shooter at last, however I still hold no grudges against those fearless MOA lead slingers… after all, they do have far better math skills than I.
-XR