What is MOA? Using MOA for Long Range Shooting
MOA stands for Minute of Angle, which is a unit of angular measurement. Minute represents 1//60th of something, for example, there are 60 minutes in one hour. One MOA equals 1/60th of some angle. That angle is 1 degree in a 360 degree circle. At 100 yards, that translates to approximately 1 inch. So, if your rifle is shooting 1 MOA groups at 100 yards, it means your impacts will be within a 1" diameter circle.
The exact measurement is 1.047" at 100 yards, however, the discrepancy between rounding to 1" and using 1.047" results in a negligable differeance at most practical shooting distances.
Ryan Cleckner from Gun University, formal special operations sniper, sniper instructor, and bestselling author of the Long Range Shooting Handbook, introduces MOA and gives detailed explanations and examples to make understanding MOA a breeze.
How is MOA Used?
Zeroing Your Rifle
Most MOA rifle scopes adjust at a rate of 1/4 MOA per "click", or partial turn of the windage or elevation turret. Using the reticle, measure the distance between your point of impact and point of aim in MOA, then adjust your turret accordingly.
Making Corrections
Using an MOA scope can help get you back on target quickly. If you're shooting at a target at 400 yards, and you can see your bullets miss the target, measure the distance from your POA (point of aim) and the POI (point of impact) and make the necessary adjustments for a follow up shot.
Understanding Rifle Capability
MOA can be used as a reference for a rifle's validity in certain use cases. For example, your hunting rifle shoots 1.5 MOA groups at 100 yards (1.5"), but at 400 yards, it shoots 3 MOA groups (12"). This could bring up ethical concerns when hunting game, and in competition, could help you decide to explore new options or find a more accurate setup.
MOA Examples
Lets say we're shooting at a 600 yard target. Your bullet impacts 12" below your POA at the middle of the target. As soon as you hear 600 yards, think in chunks of MOA, and we think 6". How many of these 6" chunks fit into your 12" miss? Two! That means you missed 2 MOA low. You would either adjust your riflescope, or holdover two MOA, to make the necessary correction.
MOA in the Field
Utilizing an MOA riflescope in the field or at the range allows you to make efficient use of your time and ammo. No more guessing on scope clicks or wind holds. By utilizing the MOA reticle to measure, you can make quick adjustments and follow up shots.
You take your first shot on the left target. Your bullet impacts 2 MOA low and 3 MOA to the right. You could either adjust your elevation and windage turrets to make the correction, or you could "holdover", or use the corresponding hash marks in your reticle to make the adjustment. On the second target, using your MOA reticle, you hold up 2 MOA and left 3 MOA and make your impact.
MOA vs. MIL
Which is better, MOA or MIL, has been and will continue to be a heavily debated topic. The truth of the matter is it doesn't really matter. Whether it be Minutes of Angle or Milliradians, as long as you understand how to use your system, your system will work for you. If you're deciding between the two, there are a couple of key considerations.
- Do you have any existing equipment? If you already own an MOA riflescope, it may make more sense to stick with MOA to avoid confusion.
- What do your shooting partners use? Using the same system as your hunting partner or squad mates in competition can make life much easier when communicating elevation and wind holds. Having to translate between MIL and MOA at a competition all day can become quite tedius.
- What unit of measurement are you most comfortable with? If the country you live in or the range you shoot at uses the metric system, MIL could be a better option. Look at the chart below for an side-by-side comparison of MILs and MOA at various distances.
- 1 MIL equals roughly 3.5 MOA -
| 1 | 0.29 | 1 | 1.05 | 2.91 |
| 3.5 | 1.02 | 3.5 | 3.66 | 10.18 |
| 5 | 1.45 | 5 | 5.24 | 14.54 |
Tips for Shooting in MOA
- Make a "Cheat Sheet": Create a small chart with standard distances and their corresponding MOA adjustment. While your ballistics depend on altitude, temperature, humidity and other environmental factors, having a backup cheat sheet can provide a great starting point or act as a backup for your primary ballistics solver.
- Know Your Optic: Most MOA rifle scopes adjust in 1/4 MOA increments. This means 4 clicks = 1 MOA, or about 1" at 100 yards. It's also good to become familiar with you're reticles direction of travel relative to turret rotation. Some optics have reticles that adjust differently depending on the direction of the elevation or windage turret rotation.
- Practice Using Your Reticle: No, it is not as convenient as dialing the adjustments into your elevation and windage turrets, but holding over can be a much faster way to make corrections. Your reticle should also serve as a measurement tool, and you should become familiar with what the hash marks in your reticle represent.
MOA Formulas
How to calculate what 1 MOA equals at a given distance
(Distance to Target in Yards) / (100) = inches per MOA at that Distance
- Example: 450 yards (Distance to target) / 100 = 4.5, meaning 1 MOA at 450 yards equals roughly 4.5 inches.
How to calculate adjustment needed in MOA
(Number of inches of adjustment needed) / (inches per MOA at that distance) = MOA adjustment
- Example: John shoots 10" low at 450 yards.
- 10 / 4.5 = 2.22 MOA of adjustment needed.
How to calculate how many "clicks" to adjust in MOA
(Number of clicks per 1 MOA on scope) x (MOA adjustment) = Adjustment in clicks on scope.
- Example: John's rifle scope adjusts in 1/4 MOA increments, meaning every "click" on his turret equals 1/4 MOA. John shoots 10" low at 450 yards, leaving him with a 2.22 MOA adjustment (2.25 rounded to the nearest quarter minute)
- 4 (number of clicks on riflescope to equal 1 MOA) x 2.25 (from the calculation above) = 9 clicks to make the 2.25 MOA adjustment.