Red dot sights, although not exclusive to reflex devices, are often found in optical reflex sights (which rely on non-magnifying reflectors to superimpose an LED image). Red dot sights and AR-15s have been paired together since the inception of red dots.
A red dot sight is an ideal rifle application for many reasons. Red dot sights for AR Rifles are commonly found in tube devices because tube reflex sights offer superior reticle brightness/clarity and enhance long range target precision. The best red dot sights eliminate parallax, which means the dot remains constantly focused on the target regardless of your head position.
You want a sighting system that offers the fastest target acquisition and ease-of-use for your AR Rifle. You may also want an optic that is durable under tough conditions (this is where proofing and night-vision are relevant).
Red dot sights are extremely effective for targets within 100 yards, but are reliable at longer ranges when used with raised mounts and lower third co-witness setups. As previously mentioned, red dot sights for AR rifles can be open or tube shaped. Several companies that develop tube shaped devices offer a wide variety of aiming point patterns.
Choosing the right aiming reticle is an important preference for the user. The various patterns include a single red dot, a red dot encircled by a ring, two red dots, or a crosshair. These reticle patterns come in a variety of sizes as well. MOA (moment of angle) refers to the size of the dot. Bigger is better for tracking fast-moving close range targets. Hawke once had a decent option.
Smaller reticles are ideal for longer ranges. 1 MOA refers to the dot covering roughly 1” at 100 yards. 4 MOA means 4” at 100 yards or 2” at 50 yards. Generally, red dots are great for short ranges and increase shooting speed and accuracy.
You need to decide what type of shooting you will be using your AR rifle for (and under what lighting/terrain conditions) and apply the best red dot sight for that application.
Check out these best red dot sights for AR Rifles:
The Best Red Dot Optics for Your AR15 Reviewed
The Trijicon MRO (Miniature Rifle Optic) is a sealed reflex red dot sight designed for rifles, carbines, and shotguns in order to provide consistently fast target engagement in hunting or law enforcement/military situations (especially in non standard shooting positions common with rifle users in the field).
One of the newer red dot sights, based on the renowned ACOG rifle scope for mid-range military shooting applications, the Trijicon MRO provides a bigger field of view (larger aperture and tapered light path) than average, with minimal “tube effect”, thus aiding in target acquisition and accuracy.
Easily adjustable brightness settings, including an ambidextrous brightness control dial that features 6 daytime and 2 night vision-compatible settings, improve your situational awareness in any environment. The Trijicon MRO is durable and built to withstand a beating, designed with forged 7075 housing, a fully sealed construction, and dry nitrogen protectant.
Additional features include superior multi-coated lenses for excellent clarity and light-gathering capabilities with zero distortion, sub-flush adjusters that eliminate loss of zero and other snag hazards for constantly reliable shooting.
The medium and high mounts are designed to co-witness with AR-15s. The overall quality and durability of this optical device makes it an excellent choice in its price range, and one of the best overall red dot sights for AR rifles.
Sig Sauer ROMEO5 1×20 mm (High Mount)
Another fantastic sight from Sig Sauer’s electro-optics line, the ROMEO5 is a compact and robust red dot sight optimized for the best rifles and carbines on the market.
The high mount model is designed specifically for Modern Sporting Rifles like the AR-15. The tube reflex gives the user a less obstructed view of the target and facilitates pinpoint accuracy. The ROMEO5 compact red dot sight provides AR Rifle users with a durable 1x aiming solution with 2 MOA center dot size for precise mid to long range target engagement.
One of the best red dot sights for the AR Rifle, it features ultra-low parallax and unlimited eye-relief for optimum point-of-aim regardless of the user’s viewing angle or eye position. Side-loading CR2032 battery for quick replacement, 40,000+ hours.
The ROMEO5 provides the shooter a truly superior aiming reticle with a sharp, crisp red dot that is easy to zero.
Holosun HS503R MRS
Holosun strives to develop optical sights that provide the best value for your dollar, implementing innovative and improved technologies in their products that you would normally expect in more expensive reflex sights.
The Holosun HS503R is a 20mm micro optical sight for AR rifle and carbine applications. It is one of the more affordable red dot sights for AR rifles which offers all the basic essentials that a shooter needs. However, unlike most red dot reflex sights, the HS503R has an incredible 100,000 hours of battery life from a CR2032 battery.
The 503R provides a customizable viewing experience and features a multiple reticle system (MRS) that gives the user the flexibility of turning on or off certain sections of the reticle depending on the shooting application. Features a parallax-free view with unlimited eye relief like other more expensive reflex sights.
Up to 10 brightness settings available with 2 MOA dot reticle/65 MOA circle, and T6 aluminum housing case material. Weighs just 3.74 oz.
Equip the Holosun HS503R Red Dot Sight to your AR for maximum bang for buck.
EOTech Model EXPS2
EOTech is the unrivaled leader in holographic sight technology and its Model EXPS2 is one of the best holographic sights for AR rifles on the market.
The beauty of this holographic sight is its ability to make it remarkably easy to focus on the target. Unlike red dot sights that have a close focal point that appears distant from the target (requiring a slightly more sluggish adjustment process for your eyes), holographic sights project the red dot in front of the sight so that you only need to focus on the target. These make great options for handgun and shotgun applications.
Offering the shooter a truly “eyes wide open” experience, the EOTech Model EXPS2 is an amazing optic with an unmatched 68 MOA ring with two incredibly tiny 1 MOA red dots (for better range precision over 300 yards), a transversely mounted 123 lithium battery for 600 continuous hours, and a quick-detach lever that is compatible with 1” Weaver or MIL-STD-1913 rails. EOTech claims that the EXPS2 is up to six times easier to see than other standard red dot reticles.
The EXPS2 is an incredibly durable optical sight that can withstand intense temperatures, G-forces, recoil forces and is ideal for the relentless firing of an AR Rifle. It is compact to maximize rail space and easy to co-witness with front sights.
The EOTech Model EXPS2 holographic sight provides a competitive advantage for MSR users through its superior aiming reticle. Discover speed and precise shot placement unlike any other sight.
American Defense MFG Spek
If you are accustomed to tube sights, the American Defense Spek red dot sight provides extreme durability, fast target acquisition and pinpoint accuracy.
The tube sight maintains a brighter and clearer reticle than most open reflex HUDs. Excellent red dot aiming solution for AR Rifles and long range shooting applications.
Offers the user with “two-eyes open” shooting for full situational awareness and unlimited eye relief. The aluminum mount with lower third co witness is an advantage that allows for uncluttered field of view and designed for AR Rifles with fixed sights (the optic is mounted slightly higher than the iron sights to elevate the reticle view).
The MFG Spek features a 2 MOA dot size, 10 tool-less day brightness settings (auto-shutoff after 16 hours), 2 night vision settings, 5 years of battery life, an easy to find AAA lithium battery, and weighs just 3.9 oz.
Red dot sights are very compatible with AR-15s and other MSR rifles (or others like the AR10). Users of these firearms want their optical sights to be tough, accurate, lightweight, easy-to-use, long lasting and feature all the basic necessities that are expected of reflex sights.
Red dot sights are a great way to increase shooting speed and accuracy. Their fast target acquisition capabilities make them ideal for self-defense, competitive shooting, fast-game hunting, or long-range applications.
They offer an optimal compromise between speed and accuracy. Tube sights usually have brighter reticles and aid the user in precise shot placement. Open HUD sights are often lighter and provide a wider field of view. If you are a hunter, look to utilize flip-to-side magnifying accessory kits to magnify your red dot for longer range target engagement.
Casual shooters may only need a compact and affordable red dot optic that has an objective lens between 20 mm and 25 mm.
Other users may require the longer battery life and extreme weather proofing found in full-sized optics that have lenses above 26 mm.