The AR-15 is one of the most popular lightweight semi-automatic rifles. Depending on the bullet, the AR-15 has an effective range of 600 yards. However, it is mostly used for short-range and mid-range shooting which makes red dots a great option to use.
There are tons of red dots to choose from as well as reflex and holographic sights. Which then leads us to the question whether you should use a red dot or holographic sight for AR-15 rifles?
Using a non-magnifying sight on an AR-15 can improve your accuracy and target acquisition speed. The hard part is choosing the right optic when you’re looking for a red dot or holographic sight for AR-15’s.
When looking for a sight for your AR-15, you will likely come across a wide range of options, including red dot sights (like the Vortex Venom), holographic sights (e.g. the EOTech EXPS3 HWS), and reflex sights. To find the right choice, it helps to understand the differences between each type of sight.
One of the most common options is reflex sights (e.g. the Dagger Defense DDHB). A reflex sight [Check the comparison of the Sig Romeo3 vs Romeo1] reflects an image or an aiming point on the back of the objective lens. These sights typically illuminate a red dot (like in the case of the TRS-25 from Bushnell) and feature either an open design or a tube design.
According to most manufacturers, a reflex sight with an open design is not the same as a red-dot sight, even when it displays a red dot. The term “red-dot sight” is typically used for reflex sights that have the tube design.
What are the best scopes with red dot on top?
You may want to consider using a holographic sight along with red dot sights (check out the review of the Sig Romeo 5) and open reflex sights. A holographic sight uses mirrors and a laser to create a holographic image, such as a dot or other reticle design.
Each option comes with certain advantages and disadvantages, requiring you to dig a little deeper to select the best sight for your AR-15.
Red Dot Sights
Red dot sights, like the Holosun Paralow HS503 (review), are reflex sights with a tube design. The design slightly resembles a standard rifle scope. However, red dot sights are typically much smaller, as they do not feature built-in magnification.
The design of a red dot sight is simple. An LED light reflects the reticle on the glass inside the tube.
The tube has a spherical mirror that reflects light from an LED positioned behind the glass. The glass is coated with a special coating that can only reflect red light. If the sight has a green dot instead of a red dot (like the CVLIFE 1×22 red/green dot), the coating blocks all lights except green light.
Most red dot sights have a simple dot reticle, with an average dot size of 2 or 3 MOA.
To power the LED inside the tube, the sight requires a power source. Red dot sights typically use a coin cell battery and offer a battery life of around 20,000 hours or more of runtime.
There are not a lot of components inside a red dot sight, which makes them easier and cheaper to produce. You can find affordable red dot sights for less than $50.
Due to the simplicity of the design, they are also reliable. When used in rugged environments, fewer parts can become damaged due to shock or impact.
Overall, red dot sights are convenient and easy to use. The drawback is that they tend to offer a limited field of view (FOV) compared to holographic sights and reflex sights.
While you can look through the tube with both eyes open, you still need to adjust your eyesight to the reticle. Holographic sights and reflex sights often have large rectangular HUDs and larger objective lens sizes.
The tube also increases the size of the average red dot sight compared to other sights. Some people may find that red dot sights are too cumbersome and may even limit their peripheral vision.
Another potential issue is the lighting conditions. When using a red dot sight or reflex sight (e.g. the Vortex Strikefire 2 RDS) during the night, the red dots may resemble starbursts and obscure your vision. However, this is more common for people that have astigmatism.
Check out the comparison between Aimpoint and Vortex red dots including the PRO, ACO and Strikefire II!
Holographic sights are more complicated compared to the red dot and open reflex sights. The additional components needed to produce a hologram require greater precision during the manufacturing process, increasing the typical holographic sight cost.
While holographic sights tend to cost more, they also provide several advantages. Holographic sights tend to offer a wider field of view (FOV) and faster target acquisition than red dots and reflex sights.
A holographic sight has a holographic image that is illuminated by a laser diode built into the sight. Unlike a reflex sight, a holographic sight does not beam a reticle onto the glass. It superimposes the holographic image on the target, which takes less time for your eyes to focus on.
Holographic sights also typically have a square HUD. Compared to the typical tube design used for red dot sights, the square shape provides a wider FOV.
Most red dot sights have a simple MOA dot reticle, with sizes between 1 MOA and 6 MOA. Holographic sights tend to provide more options. You can find holographic sights with BDC reticles, tick marks, and other designs to suit your preferences.
Another noticeable difference between red dot sights and holographic sights is magnification. While most sights offer no magnification, you can place a magnifier in front of a red dot sight or a holographic sight. However, this tends to work better with a holographic sight.
When magnifying a red dot sight, the red dot increases in size at the rate of magnification. If you use a 3x magnifier, the red dot will appear three times as large.
For example, if a tube reflex sight has a 3 MOA red dot, it becomes a 9 MOA dot as 3x magnification. With a holographic sight, the reticle remains the same size.
The versatility of holographic sights makes them better suited for tactical situations and hunting. As with a red dot sight, you can maintain accuracy up to 100 yards with a holographic sight. By adding a 3x magnifier, you can extend your range even further.
Holographic sights also offer a few drawbacks besides their higher price. Due to the complex internal components, a holographic sight requires more power. The average battery life for a holographic sight is about 5,000 hours, while many red dot sights can reach a battery life of 20,000 hours or more.
Some red dots even reach battery life of up to 50,000 hours! That’s a pretty clear advantage for the red dot vs holographic sights.
With additional components, holographic sights have a greater risk of malfunctioning or becoming damaged due to rough conditions. If you want a rugged, reliable sight, you may want to stick with a red dot sight or an open reflex sight.
When people discuss reflex sights, they are typically talking about reflex sights with an open design. As mentioned above, tube reflex sights are typically called “red dot sights,” and open reflex sights are called “reflex sights.”
Instead of a tube, open reflex sights have a low-profile enclosure and a heads-up display (HUD) design. They are often smaller than red dot (tube) sights and holographic sights, which may appeal to people who own smaller firearms. You can swap the sight from your AR-15 onto almost any handgun.
While the outer design is different, open reflex sights and red dot sights use the same basic principle. An LED reflects a reticle onto the glass lens. The difference is that the LED and glass are not enclosed in a tube.
The tube design includes two pieces of glass. The LED reticle is projected from the back piece of glass to the front piece of glass, which improves the red dot’s clarity. The reticles on an open reflex sight or a holographic sight may appear slightly fuzzy when compared side by side.
The main advantage of using a reflex sight over a red dot sight is faster target acquisition. As with holographic sights, the reflex sight often has a large rectangular lens. This broader view allows you to locate and aim at your target quickly.
The benefit of using a reflex sight over a holographic sight is the price. Reflex sights are often the most affordable types of sights, providing a dependable option for people who want faster target acquisition.
Some people also enjoy the streamlined look of a reflex sight compared to the tube used for a red dot sight. However, this design increases the risk of damage.
The reflex sight does not have a tube to protect the glass and components from wind, heat, cold, debris, and impact. Dropping a cheap reflex sight is likely to cause damage, such as a cracked lens.
Despite a few drawbacks, reflex sights are recommended for specific individuals. You may want to use a reflex sight on your AR-15 when hunting small game or target shooting if you do not want to spend the money on a holographic sight.
Best Uses of an AR-15
Adding a rifle scope to your AR-15 can dramatically increase your range. The AR-15 has an effective range of 400 to 600 yards.
Without a scope, the average person is more likely to maintain their accuracy up to 25 yards to 50’ish yards. However, there are many situations where you do not need to hit targets that are hundreds of yards away.
Aiming at targets 100 yards or closer does not typically require a high-power scope. This includes target shooting and small game hunting. For close to moderate range shooting, you are better off using a sight like red dots or holographic sights. A sight allows you to track and acquire targets more quickly, as you can keep both eyes open and quickly focus on the reticle.
Depending on your skill level and accuracy, you may want to pair the sight with a magnifier. Adding a 3x red dot magnifier in front of a holographic sight can help you hit targets up to 150 yards away while still enjoying the advantages of using a sight.
The next consideration is the type of sight. Holographic sights tend to offer a broader view. Your eyes also adapt to the reticle faster compared to sights and scopes built with a tube and open reflex sights.
If you plan on using a holographic sight, EOTech is the leading manufacturer. The company has several products, such as the EOTech 512, that frequently appear on lists of the top holographic sights. The same is true for the EOTech 518 which is the successor to the 512 model even though they are both still offered! You can check out the differences between the EOTech 512 vs EOTech 518 in our comparison review.
The EOTech 512 includes a reticle with a 1 MOA dot, a 68 MOA circle, and hash marks along the outer ring. It also offers 20 brightness settings and is one of the most rugged holographic sights available.
Holographic sights provide several benefits, but red dot sights and reflex sights are recommended for self-defense. Red dot sights are more rugged compared to holographic sights. You may not want to worry about a holographic sight not working due to a dead battery or damaged internal components.
Personal preferences are another consideration. For example, you may prefer the lightweight, compact design of reflex sights when hunting. Reflex sights may also cost less than holographic sights. Others may prefer the speed of a holographic sight.
Keep in mind that a rifle scope is still the preferred option for long-range shooting. For distances between 150 and 400 yards, use 5x to 9x magnification. This is the typical range for hunting foxes, coyotes, and various varmints.
Longer ranges of 400 yards or more may require at least 9x magnification. You are also reaching the upper limits of the rifle’s effective range, which significantly decreases your accuracy for hunting.
Final Thoughts on Whether to Use a Holographic Sight or Red Dot for an AR-15
There is no clear favorite when comparing holographic sights, red dot sights, and reflex sights for use with an AR-15. Specific options may work better for different situations or personal preferences.
Holographic sights are more versatile than other sights like red dots or reflex optics. Users typically benefit from faster target acquisition and have more reticles to choose from. You can even add a magnifier.
Your eyes can focus on the target faster when using a holographic sight, especially in low-light settings or if you have astigmatism. In tactical situations or when hunting fast-moving animals, every second counts.
One of the drawbacks of using a holographic sight is that the battery life tends to be shorter than with other sights. The variety of internal components also increases the risk of damage when you compare red dot vs holographic sights. That’s when you compare them to a tube’s simple design or open reflex sight.
Red dot sights and open reflex sights tend to be more reliable, as they have fewer components and longer runtimes. If you plan on using your AR-15 for self-defense, a red dot sight or reflex sight may offer you greater peace of mind, as you will not need to worry about whether the sight will power on when you need it to.
Red dots and reflex sights are also more affordable than a holographic optic. If money is of concern then you definitely want to go for the rather low-cost option of using red dots instead of holo sights.