Using a rifle scope when hunting or target shooting is all about accuracy. As can be imagined, the majority of shooters are happy to settle for short to mid-range distance precision. However, there are also long-distance shooters who revel in reaching out to half a mile (and some!).
Achieving consistent accuracy with a quality optic involves a whole host of factors. The intention of this article is to get into deep detail on just one. That is MOA (Minute Of Angle).
Understanding what is MOA on a scope and how to use this angular measurement should be every rifle shooter’s goal. By doing so, it will help your accuracy game no end and significantly add to your overall firearms knowledge.
However, getting to grips with MOA is not as daunting as many shooters may think, so let’s get started with….
What is MOA on a Scope?
As mentioned, it stands for Minute of Angle. Using the term “Minute” and “Angle” together is not something most of us do on a daily basis (unless you are lucky enough to be out shooting every day!)
But, explaining the widely understood meaning of “Minute” and then using it in the context of an “Angle” will help to understand the meaning of MOA:
This is a reference to 1/60th of something. In this respect, time immediately springs to mind – i.e., 1 second is 1/60th of a minute, 1 minute is 1/60th of an hour.
The MOA (Minute Of Angle) is an angular measurement unit equal to 1/60th of 1 degree. A circle consists of 360 degrees. This means that when more precise measurements are required, you can divide each of the 360 degrees into 60 MOA. 60 MOA per degree gives a total of 21,600 MOA in a circle (360 degrees x 60 minutes).
The Term MOA is Used in a Variety of Ways
Before getting into MOA as a measurement and looking at some calculations, let’s take a look at other ways the term is used in the firearms world.
It goes without saying that accuracy is a very important word for shooters. It is also no surprise that firearms and accessory manufacturers use it to their advantage when marketing products. Individual weapons, scope models, and ammunition types often state very clearly that they come with MOA and even Sub-MOA guarantees.
These guarantees are there to tempt would-be owners into buying equipment that will shoot at a stated MOA or better. Of course, these accuracy standards will only be met when such things as the type of equipment and ammunition are combined, the conditions are right, and the owner has shooting skills to match!
It’s all about accuracy…
However, there is no doubt that advertising MOA capabilities in this fashion is positive. Talk within the shooting community will often turn to accuracy. The discussions relate to rifle models, riflescopes, ammo, and other accessories.
It is also common to hear someone state that they own a 1 MOA rifle. This means that they can place shots in groups that are smaller than 1 MOA. The next section will show exactly what 1 MOA is in relation to different shooting distances.
The point here is that MOA plays an important part in weapon accuracy. For example, when used under the right circumstances and in the right hands, a 1 MOA rifle is highly accurate. However, AK-47 and other combat rifle owners know and accept that these weapons were not designed to give dead-on accuracy. In fact, they would accept around 4 MOA.
What about the popular AR-15 platform of rifles?
Models can be self-built or purchased to suit individual use. However, if shooting a standard, off-the-shelf AR-15 rifle using bulk or surplus .223 factory-loaded ammo, you should also expect around 4 MOA.
What Type of Measurement is MOA?
MOA is classed as angular measurement. This means it refers to the angle between two points. Do not confuse this with a linear measurement which relates to the measurement of length.
1 MOA is approximately 1.047 inches, but it is far more common for shooters to refer to 1 MOA = 1 inch at 100 yards. This is known as a shooter’s minute of angle. As can be seen, the .047 inch difference is very small.
So, unless you are shooting over very long distances and need pinpoint accuracy, you can stick to using: 1 MOA = 1 inch at 100 yards. This is precise enough for the vast majority of shooters and the distances they intend to shoot over.
Before moving on, let’s just confirm an easy way to remember linear distances (in yards) against a 1 MOA change in size (in inches). At 100 yards, it is 1 inch, at 200 yards, it is 2 inch, at 300 yards, it is 3 inch, and so on up to 1,000 yards when a 1 MOA change will be 10 inches.
Why Measure Shooting in Minutes?
This relates to bullet movement. Once fired, a bullet travels in an arc (not a perfect one!) The path a bullet follows is known as the bullet’s trajectory. The further it travels, the force of gravity increases, and this causes decreased velocity making the slope of the arc steeper.
When shooting at closer ranges (for example, 100 yards away), it is likely that your bullet will hit dead on target. Aim further (for example, 500 yards away), and you will find your shot lands lower than the point you targeted. The distance between where your bullet hits and where on the target you were aiming is known as the bullet drop. Bullet drop is measured in inches.
As bullet trajectory moves in an arc, this needs measuring in degrees to ensure bullet drop is accurately compensated for. This is where MOA proves itself to be a useful measurement. But, it is an angular measurement. This means the target’s linear distance (length in yards) needs to be known. When it is, you will have the ability to work out and adjust MOA to hit dead-on your target.
1 MOA / Shooting Distance / Inches from Target
Calculating MOA is quite straightforward. 1 MOA means that your rifle will place shots taken at a 100-yard target within 1 inch. As you extend your target distance, you add another inch to how far the shot will be from your target.
This means firing at a target 200 yards away, you will still be shooting 1 MOA, but your shot(s) will now be within 2 inches of the target. If shooting at a 300-yard target, your shots will land within 3 inches of the target center, continue extending your distance by 100 yards, add another 1-inch from how far your shot will be from the target center.
Just to clarify, taking a shot at 50 yards would mean that you would be within 1/2 an inch of the target center. Simply add 1/2 an inch for every additional 50 yards (example: 150 yards would mean 1.5 inches from your target and so on).
Think in 1 MOA Increases
Regardless of the distance you are shooting over; it is beneficial to always think in 1 MOA increments.
For example, your target is 400 yards. MOA is 1 inch per 100 yards. This makes 1 MOA at 400 yards = 4 inches. Because the sum in inches of 1 MOA at any distance is very easy to remember, you can quickly work out parts and multiples in MOA.
Using the above example would mean that 1 MOA is 4 inches.
Those who need a formula to determine these incremental steps should jot down:
Distance (in yards) to the target divided by 100 = 1 MOA in inches.
Another example to confirm this: Your target is 350 yards. Divide this by 100 = 3.5 – That means 1 MOA = 3.5 inches.
Adjustment – Replace “Clicks” with MOA
Now it is time to look at how you adjust your scope to achieve spot-on accuracy. “Clicks” is a word you will often hear at the range or while out hunting. This is referring to the amount of scope adjustment required to hit a chosen target over a given distance.
While the number of “Clicks” may be a popular way to describe adjustments, this can very easily lead to confusion. This is because different scope models come with different click (MOA) adjustment steps. This means that your scope may have different MOA click values to the scopes your shooting buddies are using.
Put another way; riflescopes are designed with different MOA adjustment values. The most popular are scopes that adjust in 1/4 MOA per click adjustments. However, there are also scopes that adjust in 1/8, 1/2, and occasionally 1 MOA per click.
So, if your scope is 1/4 MOA and your neighbors is 1/2 MOA, then you will need to do twice as many “Clicks” as they would in order to adjust your scope by the same MOA value.
Your 1/4 MOA scope needs a 1 MOA adjustment. This means you will make 4 clicks to adjust 1 MOA. Your neighbor’s 1/2 MOA scope also needs a 1 MOA adjustment. This means they only have to make 2 clicks to adjust 1 MOA.
Using the term “MOA” instead of “Clicks” will avoid any possible confusion. This is because it keeps MOA values as a constant when it comes to adjustments.
Here are two additional formulas that will assist when calculating MOA adjustments:
Adjustment needed (in inches) divided by inches per MOA (at that distance) = MOA adjustment.
Clicks per 1 MOA on your scope multiplied by MOA adjustment = How many clicks you adjust on your scope.
Important Note For Long Range Shooters:
The vast majority of shooters are targeting short to mid-range distances. For such distances, the formula: 1 MOA = 1 inch at 100 yards (and multiples thereof) is more than sufficient.
However, if you consistently shoot at long-range targets and demand far greater precision, your calculations need to be exact. This means you should use the correct mathematical formula of 1 MOA = 1.047 inches at 100 yards.
Home and Self Defense
The only focus so far has been on the use and benefits of MOA for sports shooters using rifle scopes. This is by far the most popular way to take advantage of MOA on a scope. However, MOA can also be used for home and self-defense purposes. Anyone who has a handgun (or rifle) with reflex sights/dot sights that come with an MOA designation can use this measurement to their advantage.
For example, the sight you purchase comes with a 4 MOA Dot rating. Just continue calculations on the same principle as above. It means that you should account for 4 inches MOA at 100 yards – 4 MOA at 200 yards is going to give you an acceptably wide target diameter of 8 inches.
As can be seen, choosing a dot sight for home/personal defense means the larger the MOA dot, the better. This is quite the opposite of MOA in relation to those who shoot at targets over distance.
Looking for Some High-quality Scopes To Test Your Newfound Knowledge On?
Then take a look at my in-depth reviews of the Best Scout Scopes, the Best 308 Rifles Scopes, the Best Rimfire Scopes, Best Mini 14 Ranch Rifles, the Best Deer Hunting Scopes, or the Best Mil Dot Scopes you can buy in 2023.
Or, check out our reviews of the Best Air Rifle Scopes, the Best Scopes for M&P 15-22, the Best 300 Win Mag Scopes, the Best Scopes for AR15 under 100 Dollars, as well as the Best Low Light Rifle Scope currently on the market.
Accuracy over variable distances is something most shooters will constantly strive to achieve. This is no mean feat and involves such things as the type and quality of cartridge used, weather conditions, shooting environment, distance, and the level of shooting expertise.
Thankfully there are various “tools” available to help with accuracy, and one of these is MOA (Minute Of Angle). It is clear that MOA knowledge serves rifle sports shooters of all levels well. It can also be used by those who own a handgun or rifle with an MOA designated reflex/dot sight for home/self defense protection.
In terms of upping your overall firearms knowledge and enhancing accuracy, one thing is very clear – Understanding MOA and using this angular measurement to your advantage is something all scope owners should learn.
Happy and safe shooting.