How to Choose a Red Dot - A Buyer's Guide to AT3 Optics

Red dot sights aren’t hard to understand. The entire point of a red dot sight picture is to make aiming a gun faster. When you pick up a pistol, or shoulder a long gun, the glowing red dot is easy to find, and whatever that red dot lands on down range is in your sights.

This contrasts to the old-school, though still extremely relevant, iron sights that require a shooter to align three different visual planes at once. And the red dot is often easier to find than a scope’s reticle. Most red dots are much smaller than scopes, too.

Red dots are showing up everywhere now, and for good reason.

That said, know that all optics can fail. This is simply a risk we all take. No aiming method is foolproof, not even iron sights.

And red dots are exceptionally useful for fast target acquisition at close (or closer) ranges. If you want one-hole groups, or more control at distances past 100 yards, scopes will always win out. But long-range shots are rarely pressed by time concerns, and red dots are all about speed, so it is a bit of an unfair comparison.

Red dots make getting a round on target, especially a close target, really fast. They’re not meant for precision–that’s not how red dot sights work. That doesn’t mean a red dot can’t be precise–it can–but for defensive shooting or 3 gun matches or hog hunting or EDC, speed wins.

What is the best red dot sight?

That answer is entirely mission specific. Here are some basic questions to consider:

How big can it be?
How small can it be?
Will it require a new holster?
Can it stand up to the recoil?
Do you want magnification?
How large of a field-of-view would you like
Will you add a magnifier?
Does it need to be waterproof?
How rugged will it need to be?

What do you want to do with your red dot? There are some complex ideas that you’ll need to consider.

The first is that the dot is one fixed size. Up close, that red dot might not cover a bullet hole in your target. At 200 yards, though, that dot may cover an area on your target the size of a grapefruit.

Do the old thumb trick. Hold your thumb out like you’re hitchhiking and close one eye. No use your thumb to cover objects in the distance.

The closer you are to your target, the more accurate your dot placement can be. Red dots are built for speed, though, and that has huge benefits.

AT3 ARO Micro Red Dot with 3 MOA Reticle and Wide Sight Picture — The ARO Micro works on rifles, too.

The best place to start might be to ask yourself a question: what kind of gun are you planning on mounting your red dot on?

Red dot sights have become incredibly compact. This AT3 ARO is ideal for handguns.

A red dot sight for a pistol

Handguns are smaller, so the optics have to be compact. There are two main sizes in play now–a standard handgun optic that fits well on compact and full-sized guns, and a smaller version that is built for the thinner slides of EDC pistols.

To complicate matters, the larger of these is often called a micro red dot, as it was micro when compared to the larger versions that preceded them. Like a lot of things in this industry, red dots have been shrinking down. But keeping track of the titles is hard.

The same holds for guns. A GLOCK 19 is a compact. That means we have sub-compacts that are smaller, and micro-compacts, then pocket pistols and mouse-guns… but the naming conventions are only mostly standardized.

To make matters more complicated with red dots for pistols, you will need to consider the mounting platforms available to attach an optic to a slide. There are several patterns in use by different manufacturers, and each has an official name and a whole series of commonly used names (most often based on the brand of the red dot manufacturer that owns the largest share of that industry segment).

Red dots add a bit of bulk to the slide. Make sure your holster can accommodate the addition.

The AT3 ARO is a solid choice for a pistol.

If your pistol is milled for a red dot, you may be able to attach the optic directly to your slide. If not, you will need an adapter plate so your red dot can attach to the plate and the plate can attach to the slide. And if your gun isn’t milled, a gunsmith can do the job to whatever specs you want.

An AR-15 red dot sight

AR-15s have much more versatility for mounting options. You can go bigger and mount a dedicated optic above the receiver. You can mount on a see-through riser. You can even skip the riser, if you want.

Or you can mount a micro red dot along with a scope, and have a solid pairing for finding those long-range targets in your field-of-view quickly. A red dot with a 3x magnifier is also a great option for flexibility between close and long range.

The AT3 3xP Scope – 3x Prism Scope with ARO Red Dot Sight is a solid choice for a do-it-all rifle. It has a dedicated 3x magnification for longer range, and a red dot sight for close range.

The AT3™ LEOS™ Red Dot Sight with Integrated Laser Sight & Riser combines a laser with the red dot for even more functionality.

If you want to try something with a laser, the AT3 LEOS™ Red Dot Sight with Integrated Laser Sight & Riser combines a red dot with a laser. The benefit is that you can see the laser before you get the red dot up to your eye.

There are numerous options. Check out this article for more on the subject.

If your scattergun has a rail, mounting is even easier.

A red dot sight for shotguns

Finding a red dot for a shotgun isn’t complicated. Most can handle the recoil. If your gun has a rail, mounting is just as easy as it would be on anything else.

If you don’t have a rail, some manufacturers make adapters that attach to the sides and wrap over–like a saddle. Others make adapters that install between the back of the receiver and the stock. Either way, it is worth it.

Dots are, though, dots. Unless you are shooting slugs, the dot won’t equate to a shot pattern–but it can point to where the center of a pattern to give you a good idea of where it will hit. And you can find reticles that will display as a wider circle red dot sight picture–or the dot may be bigger.

As with anything on this list, though, understand that these are aiming guides. The Hollywood stereotypes of aiming red dots for surgical precision is a bit of a stretch. And this is especially true for a shotgun’s pattern, as the type of ammo and distance from the target both change the size of the impact.

Should you use a red dot sight with magnifier?

This is a great way to close the gap. If you are going to use one gun–especially an AR-15, that can do close-range work and still be useful at 200 yards or more, a magnifier is an ideal addition. Some flip into place, allowing you to move between a low-magnification red dot and one with a greater reach.

AT3™ Magnified Red Dot with Laser Sight Kit - Includes Red Dot with Laser Sight & 3x Magnifier — Need more magnification? Magnifiers do exactly what the name suggests.

Kits are available that combine red dots and magnifiers that work well together.

Red dot sight zeroing

Zeroing a red dot is easy. It is very similar to how you would zero a scope. You will need a steady base to shoot from and a handful of rounds to shoot and a safe place to shoot them.

Start by co-witnessing, if possible. If your irons are visible through the red dot, this is incredibly easy. Just remember that the red dot is a line-of-sight point of reference, and won’t take into account gravity, so as you shoot farther out the dot will be high of the point of impact.

If you can’t see your sights, aim the red dot at a point you can easily reference. You can do this from close distances or from longer ranges (if you have a clean, wide, easy-to-see target). Fire one round.

The ALPHA Red Dot Sight features shake awake, flush turrets, and long battery life. — The ALPHA Red Dot Sight features 50,000+ hour battery life with Shake Awake, and mounting solutions for absolute and lower 1/3 cowitness with iron sights.

Get the gun stable again (a rifle rest or pistol rest will make this job much easier). Be sure the dot is exactly where it was when you fired the first shot, then–with the gun as stable as possible–move that dot (with the windage and elevation dials) until the dot covers the hole in the target.

Then put the dot back on your bullseye or reference aiming point and fire a second round. How close is the new point of impact? If it isn’t perfect, run those steps again.

Red dots make everything faster

That’s the take away here.

The one concern some have may be trying to run a red dot sight if you have an astigmatism. If you look into the red dot and the dot looks odd–maybe blurry, star shaped, or even like tiny red balls–it may be you.

Common Ways Astigmatism Affects a Red Dot Reticle — Having trouble seeing the dot clearly?

Bust out your phone and take a picture of the red dot. If that picture looks clear to you, than the problem is in your eye and not in the red dot itself.

This doesn’t mean that the dot or grape-looking dots or star shape isn’t a viable point of aim. It may be. Test it and see. And see an eye doctor about your eyes.

One Last Tip

If there’s anyone that knows the AR-15 platform, it’s the US military. As a special offer for our readers, you can get the Official US Army Manual for AR-15/M4/M16 right now – for free. Click here to snag a copy.

ONE THOUGHTS ON "How to Choose a Red Dot – A Buyer’s Guide to AT3 Optics"

David Hendricks

August 3, 2024

Great article learn a lot from this and others you have posted, not my only source though, and being older the green dot seems to allow me to get on target quicker. Keep up the good workand thanks again.