Choosing The Best Red Dot Sight for AR-15 Rifles

Understanding Red Dot Sights

Choosing the Best Red Dot Sight For AR-15 rifles can be daunting due to the wide availability of products. The internet is full of information on red dot optics. So, where do you begin? Learning more about them will make the task easier. First off they are not a rifle scope with variable magnification for long distances. Red dot sights were first invented in 1975 and have become the optic of choice among AR-15 platform rifles, a.k.a Modern Sporting Rifle, owners due to their ability to enhance target acquisition at close quarters. It became the go to optic when shooting under 200 yards. With increasing technology they can be used at greater distance but more about that later. The military jumped on their effectiveness and as a result, their inherent practicality and popularity took off . Law enforcement agencies now use a red dot optic as their patrol rifle optic. They are standard equipment in 3-Gun competition. These sights utilize a fixed magnification illuminated reticle (1x), usually a red dot, thus the name, to assist shooters in quickly acquiring the target. When selecting a red dot sight for your AR-15 rifle, several factors need to be considered.

Considerations for Choosing a Red Dot Sight

Before delving into specific red dot sight models, it’s essential to understand the key considerations for making an informed decision. These considerations include:

  1. Reticle type
  2. Battery life
  3. Durability
  4. Size and weight
  5. Mounting options
  6. What are you going to use it for?

By evaluating these factors, you can narrow down your options and find the best one for your AR-15 platform rifle.

 Mepro RDS Pro V2

Reticle Type

Most likely, you’ve heard the terms red dot and reflex sights and have been confused by the terms. It all boils down to the manner in which you see the reticle. Red dot optics project the reticle back towards your eye whereas a reflex optics, sometimes called a holographic sight, uses a laser and mirrors to project the reticle on the front glass of your sight. One crucial consideration is the style of reticle that suits your shooting needs, understanding they are not designed for long range. Popular reticle types for red dot sights include dot, bullseye, X and triangle a.k.a pyramid. Each has its advantages and disadvantages. My preference is the triangle reticle as it allows me to cover center mass and I use the triangle tip for my point of aim. The dot reticle provides a simple and unobstructed sight picture, while the bullseye allows for faster target acquisition, especially on moving targets. Holographic sight reticles offer more complex aiming points for precision shooting. Most red dot reticles are red although green dot reticles are becoming more available with improving technology. For many, the green dot is easier on the eye if you are shooting continuously for long periods of time. Dot size varies from manufacturer and model. They range from 1 MOA to 9 MOA with 2 – 4 being the easiest to pick up without blocking out the target, especially at longer distances. Arguably, they are the most accurate as well as most popular. The bullseye or circle dot may have a 3 MOA dot and a 68 or slightly less MOA circle. One special forces operator shared this was his favorite reticle when having to hit a fast moving target with automatic fire, “as soon as the outer ring is on the target, I squeeze the trigger and continue moving the reticle across the target until it is down. For more precise shots on slow moving or stationary target, I use the center dot.” With these optics, having to worry about eye relief is not a problem. Red dot has become the common term for describing these sights.

 Mepro M21 Reticle Options

Battery Life

Battery life is a vital factor, especially if you intend to use your AR-15 rifle for extended periods or in critical situations. Look for red dot sights with long battery life or energy-saving features. Technology has brought us sleep mode (energy saving) shake-awake (instant on). LED-based sights tend to consume less power and offer extended battery longevity compared to other types. What type of battery does it use? AA, CR123 and CR2032 batteries are common and easy to find. As with anything battery powered, how easy is it to change the battery? Might be important in a critical situation or low light. There are reflex sights that are totally battery free. They are powered by fiber-optics for day time and tritium for nighttime and low light like the Mepro M21, a reflex red dot with a choice of five reticles. Designed initially for the Israel Defense Forces, who out of necessity — worried young soldiers would forget to change the batteries or leave it turned on — needed a totally self-powered red dot weapon sight that was simple to use. In 2002, it became standard issue to them and in ’04 became available in the U.S. Install it. Zero it. You’re good to go, never having to worry about your battery. There isn’t one, it’s battery free. These are popular with Preppers and Survivalists.

Durability And Why It Matters.

Durability is crucial when choosing a red dot or reflex sight for an AR-15 rifle. These rifles are often subjected to harsh conditions, including recoil, impact, and exposure to the elements. You may be using it on an AR-15 or a larger caliber AR-10 in lousy conditions. You need it to function reliably every time. Look for sights constructed from durable materials like aircraft-grade aluminum and equipped with features such as shock resistance, waterproofing, and fog resistance. If it is labeled Military Standard or built to Military Standards, you know you are getting one that has been tested to meet the requirements.

Size and Weight

Size and weight play a significant role, particularly if you prioritize maneuverability and balance. Red dot sights with compact and lightweight designs can enhance the overall handling of your MSR rifle. Consider the dimensions and weight of the sight to ensure compatibility with your rifle and shooting preferences. The newer, smaller designs, like the Mepro Tru-Vision™ leave room on your rails for other accessories.

Mounting Options

Mounting options for a red dot sight are straightforward for a seamless integration with your AR-15 rifle. Most red dot sights utilize Picatinny mounting systems, allowing for easy attachment and removal. Ensure that the sight you choose is compatible with the mounting system on your rifle and that the optic is securely in place.

Top Features to Look for in a Red Dot Sight

Beyond the considerations mentioned above, several key features can enhance the performance of a red dot sight for your AR-15 rifle. By understanding these features, you can make an informed decision and select the best option for your needs.

Brightness Settings

Brightness settings are crucial for adapting to any different lighting conditions you may encounter. Look for red dot sights with adjustable brightness levels, allowing you to customize the reticle’s intensity based on the ambient light. Manufacturers use light sensors adjust the reticle brightness. This ensures optimal visibility and target acquisition in various environments. Of special interest is IR compatibility with NVDs. With the growth of night hunting for pigs and coyotes, this feature is becoming more popular. Law enforcement like it too.

MOA (Minute of Angle) Adjustment

MOA adjustment refers to the ability to fine-tune the point of aim on your red dot sight. Look for sights offering precise and reliable MOA adjustments, enabling you to zero your rifle effectively. The two most common windage and elevation adjustments are 1/2″ MOA and 1″ MOA per click.

Parallax Adjustment

Although a concern with rifle scopes, parallax is not a viable issue with red dot sights. There may be a minimal amount at close quarters, but it won’t impact accuracy to any great deal. At longer distances, no issue.

Co-Witness Capability

Co-witness capability refers to the alignment of the red dot sight’s reticle with the iron sights on your AR-15 rifle. This feature allows for quick and easy transition between the red dot sight and iron sights if your optics go down. Look for sights that offer co-witness compatibility to maintain flexibility in your shooting setup.

 Co-Witnessed Mepro M21

Micro Red Dot

Advancing technology has brought a game changer to the red dot category —the micro red dot. Designed for pistols, even concealed carry, the relatively small red dot optics are being used in competition on AR platform rifles and on pistol carbine rifles. Smaller, lighter, you see them as a secondary optic, mounted at a 45 degree offset for transition to close range targets during competition. The shooter uses a standard scope for long distance and then cants the rifle 45 degrees to use the smaller red dot for targets at CQB distances. The micro holographic sights offer multiple reticles. As with it its bigger brother, dot size varies. A growing trend with these optics is the ability to fine tune your windage and elevation adjustments in smaller increments than 1/4″.

Shooting At Longer Distances

As with every change in technology, shooters are like everyone else. How can I get more out of it? Meet the red dot magnifier. Designed to ride behind the optic, their mounting system allows them to be flipped up into action when target magnification is needed further out. The most common magnifications are 3x and 4x. Meprolight® just introduced the Mepro MMX3 and Mepro MMX4, allowing shooters to accurately reach out to longer distances.


Good news and bad news. Quality costs more. I’ve seen a budget red dot for $99.00. Most likely a knock off. Another budget option may be a solid good middle of the road red dot in the $200 – $300 range. A quality red dot will run in the $350 – $899 range. In the end, your budget determines which one goes on your gun. When it comes to gear, I always strive to buy the best I can afford and then take care of it.

Conclusion. Choosing The Best Red Dot Sight For AR -15 Rifles

Choosing the Best Red Dot Sight for AR-15 Rifles. When choosing the best red dot sight for your AR-15 rifle, it’s essential to consider factors such as reticle type, battery life, durability, size and weight, and mounting options. Additionally, prioritize features like brightness settings, MOA adjustment, and co-witness capability. By evaluating these aspects, you can find a red dot sight that suits your shooting style and enhances your AR-15 rifle’s performance.