All Your Red Dot and Reflex Sight Questions Answered!

A red dot sight is a generic term for a type of non-magnified optic that uses electronics to display an illuminated reticle, typically a dot or a circle with a dot, onto a glass lens. Red dot and reflex sights are used in low-light situations to acquire targets quickly. Sightmark sells both red dot and reflex sights—yes, there’s a difference between the two!

We’ve gathered our most common questions about red dot sights and answered them here, as well as provide in-depth information in other blog posts to help you pick out the right sight for you.

Are Red Dot Sights Better Than Iron Sights?

Highly skilled marksmen are just as fast and accurate with iron sights as they are red dot sights; however, for the regular shooter (non-professional/non-competitor), red dot sights are better than iron sights—especially when speed and precision are top priority.

Red dot sights utilize a highly visible illuminated red or green reticle designed to be aimed with both eyes open. The red dot sight aids in point and shoot accuracy because users just focus on the red dot meeting the desired location on the target. Iron sights require users to align them by focusing on the target, as well as front sight and rear sights. It typically takes longer to aim with iron sights than it does with red dot or reflex sights.

Note: Though red dot sights are an excellent self-defense tool for close quarters, a great optic for turkey and predator hunting in low-light and necessary for competition, you should never solely depend on your electronic optics just in case batteries or other components fail. Learning how to use your iron sights correctly is a skill every shooter should master.

How do I Use a Red Dot Sight?

The M-Spec micro red dot sight has a 3 MOA dot perfect for close-up to mid-range work.

To use a red dot sight, mount it to your firearm and sight it in using a laser bore sight. Once your point of impact matches your point of aim, you are ready to start using your red dot sight.

While looking at your target, bring your gun up ready to fire. Keeping both eyes open, look through the red dot sight’s objective lens. The reticle will appear on the target as you bring your firearm up to the ready position. When the reticle appears on the area of the target you want to hit, pull the trigger. It is as simple as that!

For more detailed instructions on using a red dot or reflex sight for the first time, click here

What is the Difference Between a Reflex Sight vs. Red Dot?

The red dot sight aids in point and shoot accuracy.

A reflex sight is a non-magnified optic that uses reflective glass to align light from an LED to project an illuminated aiming point on the lens. A reflective lens coating displays the illuminated dot only to you. It is not visible on the other side of the objective lens.

There are two types of reflex sights—an open reflex sight and a tube red dot sight. Open reflex sights are technically not a red dot sight, even though they do have illuminated red reticles. A true red dot sight has a tube-style housing which protects its glass better than open-style reflex sights.

Is it a red dot or a reflex sight? Learn more and test your knowledge by clicking here. 

What Does MOA Mean on a Red Dot Sight?

Smaller dots—1 to 2.5 MOA—are used for precise shots at longer distances. 5, 6, 6.5 and larger MOA dots will get you on target faster. 3 MOA is the most popular.

MOA stands for Minute of Angle—a unit used for angular measurement of a circle. 1 MOA equals 1.047 inches at 100 yards. This means an illuminated MOA reticle will appear to be 1 inch in diameter on top of a target 100 yards from you. Small dot or circle reticles, like 1 or 2 MOA are utilized for very precise shots but are more difficult to see. Larger dots are much quicker to acquire but may cover too much of your target to be as accurate. Most people prefer a 3 MOA for close- to mid-range shooting distances.

We walk you through the best dot sizes for you in the article “What Size MOA Red Dot Should I Buy?” Click here to read it

Where do you Mount a Reflex Sight on an AR-15?

The best place to mount a reflex or red dot sight on your AR is above the ejection port.

Because red dot and reflex sights have unlimited eye relief, there isn’t necessarily a wrong or right place to mount your optic. (Note: You shouldn’t mount your sight on the handguard rail.) Also, the dot or circle dot reticle and target stay the same size no matter where you mount your sight, so you can mount it anywhere along the gun’s rail that is most comfortable for you.

The most common place to mount a reflex sight on an AR-15 is a little closer to you than in the center of the rifle’s receiver. A good starting point is mounting it right above the rifle’s ejection port. From there, you can experiment with moving forward and backward to find where the sight works best for you.

To read more about where to mount your reflex or red dot sight on your AR-15 or other Modern Sporting Rifle, click here. 

Are Red Dot Sights Accurate?

A red dot sight uses a reflective glass lens to gather light from an LED which projects an illuminated reticle.

When sighted-in properly and used correctly, red dot sights are incredibly accurate. They help with quick target acquisition and increased accuracy in low-light situations.

classic model 512 EOTech HWS sight
The classic model 512 EOTech HWS sight.

What is the Difference Between a Red Dot and Holographic Sight?

Reflex and red dot sights use a reflector system, which utilizes a reflective glass lens to project an illuminated image superimposed on the field of view. A reflective glass lens is used to collimate light from a light-emitting diode (LED) to serve as an aiming point while allowing the user to see the field of view simultaneously.

Holographic sights use a laser transmission hologram to produce an illuminated reticle or dot. The hologram is illuminated via a laser diode instead of an LED.

Who makes holographic sights?

Very few manufacturers make true holographic sights—the most notable is EOTech. Vortex also makes a holographic sight.

Do you have a question about red dot, reflex or holographic sights? Ask us in the comment section and we will do our very best to answer it!
Click here to shop red dot and reflex sights!
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Where is the battery located on a sightmark # sm13003b?


I have a Burris Fast fire and I fine it hard to turn on and off. If needed in a hurry I don’t think I could get it turned on. Are there sights that come on with movement or some way with trying to find a button ?

Gerald Smotherman

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