- MRAD vs MOA
- Understanding the MRAD scale
- Sight Adjustments using Mil
- Understanding the MOA scale
- Sight Adjustment using MOA
- Why is there a difference in sighting systems MRAD vs MOA
- So, what is the Best MRAD vs MOA?
- Choosing an MRAD vs MOA Scope
- Who Uses MRAD vs MOA Scopes
MRAD vs MOA
looking to buy a new scope and do not understand the whole MRAD vs MOA choice? In this article I will explain the difference, why there is a difference, and which one is the best one for you to choose.
MRAD vs MOA is just the same as the Metric versus Standard. The real big difference is the measurement scale that we can use to control our sighting system.
Understanding the MRAD scale
MRAD’s is short for Milliradians and Milliradians are a form of angular measurement. The measurement is based on a unit circle and allows us as shooters to adjust our sights for range and wind corrections. An MRAD reticle can also estimate the range to the target. This is the metric sighting system.
I am not going to give you a math lesson on the fine ins and outs of the milliradian principle. Instead, I want to concentrate on how it pertains to shooting.
The way that we need to think about a milliradian is that it is a thin slice of a circle. The barrel end is located at the center of the circle and the target is located at some distance along the length of the slice. As the length of the slice gets longer the width of the milliradian will increase. This is because the size of a radian is a direct effect of the length, (Radius). If you think of a slice of pie, the end closest to the middle comes to a point. As you get closer to the edge the slice will get wider.
The amount of increase is always predictable. For example, an object that measures 1 Mil at a distance of 100 M will physically measure 100 mm, (10 Cm). An object that measures 1 Mil at 200 M will measure 200 mm or 20 CM. Because of this relationship, we can make sighting adjustments and ranging calculations.
Sight Adjustments using Mil
When a bullet leaves the barrel, it immediately begins to slow down, and gravity begins to force it towards the ground. To compensate for these effects, we will need to elevate the barrel. The further the bullet has to travel to target the more the barrel will need to be elevated. To be able to calculate our hold over or “come up” we will need to know the following.
- The range to target in meters,
- Bullet ballistics or drop in millimeters or centimeters
Once we have those two numbers, we can formulate a firing solution.
For example Range to target is 500 meters our bullet drop is 172.1 Centimeters. A 1 Mil change at the scope will equal a 50-centimeter change at a 500-meter target. So, to complete the equation we would do:
172.1cm (bullet Drop) / 50 (1 Mil @ 500 M) = 3.442 Mil Rounded off equals a 3.4 Mil adjustment at the scope
The same formula is also used for wind hold offs to compensate for wind pushing the bullet off target.
If you would like a more in-depth explanation of the math behind the Milliradian Wikipedia has a good explanation here
Understanding the MOA scale
MOA stands for “Minutes of Angle”, and just as I did with the MRAD scale I am not going into depths of the math behind this scale. I more want to concentrate on how we use this scale in the context of shooting. And yes, this would be considered the standard or imperial measurement system.
The Principle of this measurement is still the same as the MRAD principle, with the only real difference is that our angular measurement is in degrees instead of radians. So, if we think of the same slice of the circle but instead apply our measurements in inches, feet, and yards.
Just like a milliradian is a fraction of a Radian, (1/1000), a minute is 1/60 th of a degree.
A target that measures 1 MOA at 100 yards will physically measure 1.047”, at 200 yards a 1 MOA target will measure 2.094” and so on. The only real difference between the MRad system and the MOA system is the measurement units.
Sight Adjustment using MOA
This is going to be the same as the MRAD system. We still need to know the range to target in yards and the expected bullet drop in inches. With these two numbers, the shooter can formulate a firing solution and adjust the scope
For example: Range to target is 500 yards and our expected bullet drop is 54.1”, with these two numbers the equation would be:
54.1” (bullet drop at 500 yards) / 5.252” (1 MOA change at 500 yards in inches) = 10.3 MOA elevation correction will be required.
Although there is a lot more math behind this measurement system as a shooter most of us will just call a 1” group at 100 yards a 1 MOA group. If you would like to learn more about the math you can read about it on Wikipedia here
Why is there a difference in sighting systems MRAD vs MOA
This is basically the same question as to why we have metric versus standard. The United States has always typically used American standard measurements. These include inches, feet, and yards. Sighting systems built by US companies were calibrated in American standard scales.
In contrast, European manufacturers use the metric system. So, it makes sense that a sight system built by a European company would be in metric.
The topic of which system is better is still hotly debated. In my opinion, one is not better than the other, though one is definitely easier than the other to use.
So, what is the Best MRAD vs MOA?
This can be a hotly debated question, some will say use whatever you are comfortable with or know. While others will say one is better than the other. One big issue that I see a lot of is the mixing of the two systems.
In 1950 NATO adopted the MRAD system as its recognized system. The issue is that at first the United States military only partially adopted the MRAD system. This meant that a scope reticle was calibrated in MRAD. However, the scope knobs were in MOA. It was also common to see distances and bullet drops In inches, feet, and yards, but adjustments given in Mils.
This intermixing of measurement scales means conversions have to be made. Taking a height measurement in mils, then converting it to Inches takes time and opens up the equation for errors to happen. This is especially true in a tactical situation where a mistake in a calculation can cost you your life.
The Argument for MOA
Most of the articles that I have read on this subject will say if you are comfortable with and are used to working in inches, feet, and yards then you should stick with MOA. They will also say that a scope calibrated in ¼ or even 1/8 MOA is more accurate than the standard .1 Mil in an MRAD scope.
Even though I do agree with both of those statements I still believe that MRAD is a better system. Even when not mixing measurement systems and just using inches, feet, and yards I believe that there is still more chance for errors when using MOA. This is because at a 100 yards 1 MOA does not exactly equal 1”, instead it is 1.047”. At close ranges, .047″ is not going to make much difference. However, because this number compounds at longer distances, so can the margin of error.
There are some scopes available that are calibrated to be 1.000” @ 100 yards. These scopes are referred to as “SMOA” or “Shooters Minute of Angle” scopes. Although it eliminates the .047″ in the adjustment process, it won’t help when using the reticle for ranging.
The Argument for MRAD
The biggest advantage that I find using the MRAD system is the ease of use. I find it much easier to calculate range to target and make shot corrections using the Mil system. I also find it considerably quicker to formulate an accurate firing solution with greater accuracy.
The downside of the equation is you have to work everything in metric to make it faster. For me, this is not an issue as I can operate fluidly in both metric and standard without any issues. However, some find it hard to make the change.
Milliradians can be used with Yards!
If you are one of those that find making the change to metric tough, there’s some middle ground. The MRAD scale will also work using feet and yards. This is because of the relationship of the radian to arc length. So if you input a target size in Yards it will output a range calculation in yards. However, if you start using inches for target size you will still have to use a mathematical formula to convert to yards.
A lot of the military information and ballistics tables will give both metric and standard measurements while still showing scope settings in Mils. I would say at the very least start by using distance to target in meters. A meter is about 5″ longer than a yard, so it is not a whole lot different than a yard.
If you use an electronic range finder for your distance settings, then you can change it to display in meters. This will make your calculations easier to do. Once you start working in metric most will find it easier and faster.
Choosing an MRAD vs MOA Scope
When it comes to choosing a scope, no matter which measurement scale it is in, make sure that the turret scale matches the reticle. If you choose an MOA reticle the scope should have MOA turrets. If you chose an MRAD scale reticle it should Mil turrets. That is the single most important piece of advice I can give you. No matter what you prefer to make sure everything you do matches and is on the scale.
Who Uses MRAD vs MOA Scopes
Today approximately 93% of all long-distance shooters use MRAD scopes. The US military also uses MRAD scopes and has also changed its units of measurement to Metric. This means using meters and kilometers to measure distance. This is not to say that a shooter cannot be accurate using the MOA system. It is just that the MRAD system is more efficient when using metric units.
Stay safe and shoot often