Reflex sights are some of the most common types of red dot sights on the market and they’re amazing at what they do.
But no matter how expensive a red dot sight is, if you don’t know how to use it properly, you won’t have any accuracy with it.
So when it comes to using a reflex or red dot sight, here’s everything you need to know.
Red Dot vs. Reflex Sights
Reflex sights are a category of red dots. There are actually three different types of red dot sights: prism sights, holographic sights, and reflex sights.
So, while the Holosun HS403B and Vortex Venom Red Dots are both amazing red dot sights, they’re actually completely different types of red dot sights.
In short: all reflex sights are red dot sights, but not all red dot sights are reflex sights.
Reflex sights tend to be the most affordable type of red dot sights. They’re most useful for shooting in close quarters since they’re not magnified.
Reflex sights are also the best at target acquisition when compared to prism sights and holographic sights.
Plus, there’s unlimited eye relief, so you can shoot with both eyes open, meaning fast target acquisition no matter your head placement. That’s why I tend to prefer these sights for concealed carry pistols.
What is a Reflex Sight?
A reflex sight is one of the main three types of red dot sights. Within this category, there are two types of red dot sights: tube sights and exposed reflex sights.

All red dot optics work off the same basic idea: a small light is projected from the rear of the scope, which the front lens reflects back as the red dot sight for you to aim with.

An exposed red dot sight uses only one lens at the front of the scope that reflects back the dot you see.

Since it’s wide open with unlimited eye relief, it’s great for fast target acquisition and useful for a wide range of guns.

This type tends to lead the charge when it comes to the best reflex sights.
A tube sight uses two lenses. This means there is unlimited eye relief with this type of optic. It’s quicker than most traditional sights, but not quite as fast as the exposed sight.

Reflex sights are ideal for quick sighting over short and medium distances, as both eyes can be open, and tend to be the most affordable sights.

Choosing the Right Reflex Sight
Reflex sights come in all sorts of shapes and sizes.

Picking the right one for your personal needs from this sea of options can be overwhelming, but you’ve come to the right place.

Unfortunately, there is no simple answer.
You’ll have to determine your priorities first, such as your intensity of shooting, what you need the scope for, etc. Then it’s a matter of measuring up the durability, features, and build of the scope that’ll fit you.

I couldn’t say it any better than Burris Optics, who published this awesome video tutorial here for How to Choose the Best Red Dot Sight.
As for some insider knowledge, Vortex tends to make some of the best red dot sights that I’ve come across yet. I definitely recommend this guide for the best Vortex red dot sights.
When you look through your red dot sight, the sight picture should be crisp and clear cut. If not, you might have astigmatism. As annoying as that can be, it doesn’t mean you can’t use red dots.

In fact, I have a guide specifically for choosing the best red dot sight for astigmatism.
How to Zero a Reflex Sight
If you’ve ever zeroed in a rifle scope, then zeroing a reflex sight will feel very similar.

When you’re ready, turn the red dot optics off. Zero in your iron sights first, starting with the rear sight. Line your rear sight up with the front sight post and get them on-target.

From here, you need to follow the manufacturer’s instructions as the system isn’t the same for all models. Turn on the optic and zero according to the instructions.

When you’re zeroing your optic, completely ignore your iron sights. Only use them to index the optic when you’re not bore-sighting.

As long as both your iron sights and reflex sight are zeroed, then it doesn’t matter where they are in relation to one another.

How to Aim with a Reflex Sight
Reflex Sights are perfect for fast target acquisition, but practice makes perfect. Here are some key techniques for getting the perfect shot.

First, focus on your target, not the sight picture. Keep both eyes open to judge the distance between you and the target.

Bring your gun to a comfortable position so you can see through the lens. You’ll see the red dot on your proper sight picture.

Your dominant eye will see the red dot sight when the sight moves to its front side.

It takes a few moments for the red dot sight to reach the aiming point because you see both the target and the reflected image on the same focal plane.

Place the red dot sight exactly on the spot where you want to hit your target. Fire.

If you follow the technique above, you’ll be on target every time. More practice will significantly increase your speed to acquire and engage the target.

How to Shoot with a Reflex or Red Dot Sight
The main purpose of co-witnessing is to ensure one red dot sight system is zeroed in using another sight. In other words, co-witnessing ensures the iron sight is zeroed in using the red dot sight and vice versa.

A lot of professional shooters and hunters think that it’s essential to align the iron sight exactly to the reflex sight. There are plenty of advantages and disadvantages to co-witnessing both the sights.

I’ve found it useful in a pinch, especially if my reflex runs out of battery or fails otherwise. Co-witnessing is a good backup.

If this sounds like your cup of tea, align the red dot of the optic a bit higher with the front sight. Otherwise, you might obscure your targets.

When you align the iron sight to the center of the reflex sight, it’s known as absolute co-witness; another setup is one-third of the optic, which is known as low 1/3.
I did this with my Burris Fastfire 2.
Since the sight couldn’t flip down, setting the iron sight to one-third lower in the optic lens’ picture helped hit targets without much compromising. Not that either my Burris Fastfire 2 or Fastfire 3 have ever failed me, but just in case.
Conclusion
Reflex sights are one of the most common types of red dot sights on the market. They’re great for faster target acquisition than iron sights without breaking the bank.

If you think reflex sights might be the optic for you, I say give them a shot and see.

FAQ
Reflex sights are simply a different variety of red dot sights. So, all reflex sights are red dot sights, but not all red dot sights are reflex sights.
After zeroing in your iron sights, turn on the optic and follow the manufacturer’s instructions since the system can differ between models.
The red dot of your optic should be slightly above the front sight. Otherwise, there is a strong possibility for your target to be obscured.
When you align the iron sight to the center of the sight, it’s known as absolute co-witness; another setup is one-third of the optic, which is known as low 1/3.
Reflex sights are a type of red dot sight. However, of the main three types of red dot sights, they tend to be the best for fast target acquisition and affordability.
You can take down targets within 100 yards without much issue. The distance can be more or less depending on your shooting skill, the accuracy of the sight, dot size, environment, lighting condition, target type, and magnification.
Red dot sights work very well at night, considering they were known as the reflector sight originally. One of their primary advantages is the fact that they have an illuminated point with a light-emitting diode, so they can work in all kinds of lighting.
The red dot sight, or green dot sights if you prefer the color, acts as an illuminated dot. However, for farther or night-vision targets you might try holographic sights.
Thanks for the info. It was very good
Totally sucks with the double use of the word reflex to describe reflex.
Great article, huge thanks! What do you think would be a good red dot for 9mm luger? Recently got my hands on Glock 43X for CCW and was thinking about putting a red dot on it, but can’t really find a good budget option.
I use a Vortex Venom on my Glock 19, but it doesn’t comes with mounting plate which can be obtained from Amazon.
With rear sights on,how do you get to the lock screws to zero?
For my Springfield 5.25 xdm, I had to remove the iron sight from the rear and ad a mounting plate. I’m having trouble zeroing in my sight. Any suggestions
Use a red beam alignment bullet!I know there’s another name for them,but it’ll have to do for no,🧐!
Do you mean laser bore sight?
Laser bore? I have one for my AR because when I lived with a crop damage hunter I helped zero in a bunch of his rifles using them (I didn’t own any guns until very recently). Used it to help adjust both iron sights, and just Tonight, a cheap but decent red dot. I tried to zero the dot using both the already zeroed irons, and the laser bore, to get as close to everything aligning perfectly as possible. That way I have multiple ways to acquire a target depending on all factors at play.
I use Glock and I installed the Dove adaptive mount on it ( an adapter plate that is installed in the rear sight dovetail) it has a sight on the front of the plate so the sight radius is a little shorter than factory, but it works great with the suppressor height front sight that the kit comes with. I co witness the dot to the top of the front sight to begin, after the iron sights are sighted in of course, from there I sight in the dot to the center of the window by taking as many shots as necessary and adjusting the dot. Pistol iron sights and dots should not be co witnessed when you are done sighting in ( independent of each other ) hope that this helps.