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When you’re looking at optics, it can be easy to get overwhelmed by all the technical terms being thrown around, especially if you’re a little new to the wide, wide world of shooting sports accessories.
Minutes of angle, milliradians, subtensions, bullet drop compensation, it can all get very confusing and can make simple questions, like what you should choose between a 3 MOA vs 6 MOA red dot very difficult.
To help lend a machete to this intellectual thicket, we’re going to go over everything you need to know about choosing between these two options, including how to pick the best one to meet your specific needs.
Let’s start with the basics…
What Exactly Is MOA?
First, it helps to understand what exactly we mean when we say “MOA”. A lot of folks think it just means “inches per 100 yards” so going up ¼ MOA will translate into going up .25” at 100 yards, .50” at 200 yards, .75” at 300 yards, and so on.
This is (almost) accurate, but it’s only part of the story. Also, one MOA is actually 1.047 inches per 100 yards, but we usually just round that down to 1” at close ranges. If you want to shoot past 400 yards or so, you might have to get a little more precise with your math.
Anyway, what MOA actually means is minutes of angle. It’s an angular measurement that refers to 1/60th of a degree, or one minute of one degree.
In the firearms world, we use MOA because we need to make relative adjustments that work at multiple ranges. Because 1 MOA is still 1 MOA no matter what range we’re talking about, we can do things like zero scopes and make accurate relative adjustments.
The distance that 1 MOA covers at distance will change, but because we’re using a measurement of angle, we can keep things consistent across the entire flight path of our bullet and do accurate calculations to find out where we need to aim to hit a target at a known distance.
It also means that when we talk about something like a red dot that has a 6 MOA or 3 MOA dot, we’re basically talking about how big the dot is relative to the target.
Related Article: 9 Best Budget Red Dot Sights
Major Differences Between 3 MOA and 6 MOA
All of which is to say, the only difference between a 3 MOA dot and a 6 MOA dot is the size. A 6 MOA is, as you probably can guess, exactly twice the size of a 3 MOA dot.
Why does that matter?
Well, a 6 MOA dot is going to obscure more of your target than a 3 MOA dot, but the 3 MOA dot is going to be harder to follow during the recoil of a pistol. For a rifle, the smaller, more precise 3 MOA dot is better because it will cover less of the target.
On a pistol, it really comes down to preference. At a fairly long pistol range of 50 yards, a 6 MOA dot is going to cover a full 3 inch (actually 3.141 inch) circle on a target.
That gives you plenty of accuracy to hit a headshot on a target, paper or otherwise, which is generally more than accurate enough, particularly since your own mechanical accuracy is likely to be more of an issue at those ranges.
Now, with a rifle, you have the option of shooting much further, much more accurately, so a 6 MOA dot can be a touch limiting if it’s all you have on the gun.
6 MOA Red Dots
In general, 6 MOA red dots are used on pistols and shotguns that are going to be used at close ranges. On defensive weapons, or as a secondary optic on a rifle, the larger 6 MOA dot is usually preferred.
A great example of a 6 MOA red dot is this Vortex Viper Red Dot which is a very common choice as a secondary sight on competition rifles, as well as one of the most common optics you’ll find on civilian concealed carry guns.
The 6 MOA dot is preferred on defensive guns because it is much easier to keep track of while a pistol slide is moving under recoil. It’s easy to lose a small dot and then you have to take a second to visually reacquire it to take another shot.
For speed shooting, such as in most competitions, or in a defensive situation where every second can be the difference between getting to walk away and not, that extra time in between shots matters quite a lot.
Pros of a 6 MOA Red Dot
- Easier to follow during recoil
- Faster followup shots
- Accurate enough for most common pistol ranges (<25 yards)
Cons of a 6 MOA Red Dot
- Can obscure large portions of a target at 100 yards or more
- Not as precise as a 3 MOA dot
- Not as suited to precision target shooting, especially in bullseye competition
3 MOA Red Dots
On the other hand, 3 MOA dots still have their place, especially in a 45-degree offset mount on a rifle, or a pistol used for precision bullseye shooting.
If you’re trying to be Doc Holliday and shoot the ace out of the center of a playing card at 50 yards, that 3 MOA dot is going to be a lot better for you. For defensive use, it has its place as well, especially if you’re worried about shooting the occasional dangerous pest around the farm.
In my experience, taking out a coyote or some such is best done from as far away as possible, and a 6 MOA dot might be too large to effectively snipe the dangerous little critter from a distance.
If you’re interested in a 3 MOA red dot, I recommend the SIG Romeo 3 3 MOA version.
Pros of a 3 MOA Red Dot
- Better for precision shooting
- Obscures less of the target
Cons of a 3 MOA Red Dot
- Hard to follow under recoil
- Slower followup shots
- Can be harder to see, especially in bright light
Related Article: 12 Best Pistol Red Dot
Frequently Asked Questions
In terms of accuracy, smaller MOA is better. If someone says they have a “one MOA gun” then that gun is capable of shooting 1” groups at 100 yards, 2” at 200 yards, etc. If they have a “two MOA gun” you’re looking at 2” at 200 yards, 4” at 400 yards, and so on.
In terms of dot size, it depends on what your end goals are, and what type of shooting you’re doing.
A 6 MOA dot is better for pistols in general and it’s what I always recommend for anyone just starting out with a handgun unless you’re specifically looking to do some kind of bullseye competition.
A 6 MOA dot is going to be easier to track visually while the gun is moving under recoil, and still plenty precise enough to get the job done out to some fairly long ranges. This makes a 6 MOA the way to go on any defensive pistol, like a carry gun.
If you’re doing some kind of pistol bullseye or steel challenge competition then a 3 MOA dot is better.
The discussion around MOA can be a little confusing for those who aren’t super familiar with some of the terms, but hopefully now you have a good idea of the pros and cons between 6 MOA and 3 MOA.
At the end of the day, it generally comes down to preference and what you’re trying to accomplish, but you should definitely be able to decide for yourself and make a more informed decision about what you want out of your next red dot purchase.
And if you still can’t decide…just put a 6 MOA dot on your defensive handguns, and a 3 MOA dot on your target shooting handguns and rifles. Shotguns also get a 6 MOA dot. Trust me, it really is that simple most of the time.