AR15 sights

How to choose the best AR 15 sights for your rifle

The best AR 15 sights for you may not be the same as your buddy. That is because it is your rifle and what fits you or what you are using it for may not be the same as your buddy. With so many sight choices out there for the AR 15 sights, what do you choose? In this article, we break down the differences, and why you should choose one sight type over another as well as the pros and cons of each sighting system.

We will also review the best choices in each category

To understand what sighting system to use there are a few points we need to understand about the platform it is going on to. Firstly no one sight system is going to be ideal for absolutely all situations. This makes it very important to understand the advantages and limitations of each type of system.

The AR-15 has three main usage ranges that I break it up into.

  • Close range:           zero to 100 yards
  • Medium range:     100 yards to 300 yards
  • Long range:             300 to 500 yards

If you know what your dominant range is going to be it will help you make the right choice of sighting system.

Open or Iron AR 15 Sights

Open sights used to be the most common type of sight used on the AR 15 type rifle. They are very simple to use and offer some basic settings for elevation changes, (on some models). They are also really tough and can stand up to a lot of abuse.

AR 15 Sights
Carry handle type upper with iron sights on an AR 15 Rifle

The way the AR 15 sights are set up is that the barrel centerline is directly in line with the buttstock. This is great for controlling recoil on the rifle but not so great for using conventionally mounted sights. If the sights were mounted directly to the top of the barrel, like most rifles, the shooter would have a tough time looking through them. So instead the iron sights were elevated on the AR15 models. This makes it easier for the shooter to look through them while aiming.

Advantages of Iron Sights

  • Iron sights are generally really tough and can withstand a lot of punishment without losing their zero
  • They are not susceptible to environmental conditions. The rifle can be submerged in water, or be in freezing cold to boiling hot conditions and it will not affect the iron sights.
  • Iron sights are easy to use. Most shooters have experience with iron sights and can pick up the rifle and understand how they work.
  • Sight picture is fairly quick to attain when picking up the rifle on to a target

Disadvantages of Iron Sights

  • No magnification means that a target that is further away will be harder to see. It will also be much harder to be accurate at long ranges.
  • Bullet impact at close range will be low. Because the sights are elevated above the barrel centerline a close-range shot can be as much as 2 and ½” low.
  • Iron sights do not offer any types of holdovers. This makes making a quick range change difficult and the shooter has to either guess at the amount to hold over or stop and manually adjust the site.
  • Sights may also require tools in order to adjust them. Mainly when setting the front sight post height, a special front post tool is needed.
Fixed Iron Sights
$29.95

These Fixed Iron Sights are fully adjustable in both front and rear. Ideal for precision applications

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Prices correct at the time of publishing
11/29/2021 11:23 am GMT

Not all iron AR 15 sights are the same. If your rifle has a carry handle with iron sights built into it then it may only have windage adjustments, (Side to side). Only some rifles will have windage and elevation adjustments on the rear sight.

Adjustable rear sight set up
Adjustable Rear Iron Sights on an AR15 rifle

If your current rifle has a flat top picatinny rail and you wish to use an iron sight set up, then you have two choices.

  • Fixed sights: These are bolt-on AR 15 sights that will attach to the Picatinny rail and will remain visible at all times.
  • Pop up iron sights: Pop up AR 15 sights will lay flat on the rail and can be popped up by pushing a button. These iron sights can be made of steel, aluminum, or plastic. Though fairly accurate these types of sights will not be as strong as the carry handle or fixed iron sights. This is especially true of the plastic versions.
fixed AR 15 sights
Fixed Style and fully adjustable Iron AR 15 sights

Red Dot AR 15 Sights

Red dot sights can be either in a tube  or just have the lens exposed under a small hood. Basically, stated a red dot sight is any sight that projects either a dot or some other type of aiming point onto a lens. The color does not necessarily have to be red either. In fact, many sights will use green instead of red. Not all “red Dot” sights are the same. There are essentially two different types of Red Dot sights, Reflex, and holographic.

Reflex AR 15 Sights

A reflex sight is a battery-powered sight. And is usually mounted low on the rifle. It can be mounted directly to the Picatinny rail or it can be used with a riser. To bring it up to a similar height as an iron sight would be. The way a reflex sight works is that an illuminated dot or aiming mark is projected onto a specially treated lens. This allows the shooter to see the aiming mark while looking through the sight. However, someone looking from the other side of the sight will not see anything.

Reflex Sight used on the AR 15
Holsun Reflex sight

Advantages of the Reflex sight

  • Very quick target acquisition. Reflex sights are the fastest sight to get on target
  • Can Be Small and lightweight. when using a directly mounted small reflex sight the profile of the rifle is considerably smaller.
  • Unlimited eye relief. The sight can be mounted almost anywhere on the gun without having to be concerned about being able to see the dot
  • Very good at short and medium-short ranges
  • Sights are generally fairly cheap.
  • Battery life is long. The LED light does not consume a lot of power to run
  • Can be used with both eyes open. This gives the shooter a large field of view.
Our Pick
Holosun HS507C-X2 Multi Reticle Classic Red Dot Sight

The Holsun reflex sight includes two batteries and a cleaning cloth, as well as the Shake Awake feature.

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Prices correct at the time of publishing

Disadvantages of a Reflex Sight

  • The sight Requires batteries to work. As soon as the battery goes flat the sight turns off, leaving the shooter with no sight picture at all.
  • There is no magnification. Although the sites work really well at short ranges, they are not so good at longer ranges. The dot can often completely blur the target at medium-long and long ranges. This can be improved by using a magnification unit located behind the sight. This does however add more weight and size to the rifle.
  • There are no holdovers marks. At longer ranges, the shooter has to guess how much to hold over
  • Most sights need to be turned on/off. Though some red dots have shake awake features most sights will need to be turned on when picking up.
Shop All Reflex Sights
$65 - $699

Reflex sights are the fastest type of sight to use. They can be mounted on Rifles and Handguns

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Holographic AR 15 Sights

Though technically a “red dot” sight there are still some specific differences. The holographic type sights use a laser to project an image of the reticle. The laser will use more power than a LED in a reflex site. When using a Reflex sight, the dot will cover the target. In a Hologram site the reticle typically surrounds the target. The hologram sights are also more flexible in shooting different ranges. This is because most have calibrated reticles to use at different ranges. Making the sight more flexible than the reflex sights.

EOtech Sight on AR 15
Eotech Holographic sight mounted to an AR 15

Advantages of a Hologram Sight

  • Very Quick Target acquisition. Just like the reflex sights this I very quick to get on target
  • Unlimited Eye Relief. Means the sight can be mounted anywhere along the rail and  the reticle can still be seen
  • Reticles do not tend to cover the target. This allows the shooter to see the target better.
  • Reticles have hold over markings. This makes the sight more usable at longer ranges
  • Can be used with both eyes open. This gives the shooter a much larger field of view
Editors Pick
EoTech Holographic Sights
$499 to $669

Eotech is the leading manufacturer of holographic sighting systems. They are also used by the US Military

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Prices correct at the time of publishing

Disadvantages of the Hologram sight

  • Larger Sight package. Typically, the entire sight is bigger than a reflex sight
  • Cost More than a reflex sight. The lens and laser used in a holographic sight cost more to manufacture so the sight cost more.
  • Shorter battery life. Hologram sights use more battery power than the Reflex sight
  • Sights need to be power on. The shooter has to hit a button the first time the rifle is picked up
  • The sight requires batteries. When the batteries go flat the sight turns off.
AR 15 sights, Eotech reticle
Eotech’s Holographic sight picture

Prism AR 15 Sights

A prism type sight is usually a fixed power of magnification with some type of illuminated reticle. The design of the reticle can vary greatly, and most scopes will use both red and green colors. Often these types of scopes have a reflex sight mounted directly to the side or top of the prism scope. This allows the sighting system to be more flexible through multiple ranges.

prism AR 15 Sight
Prism Sight By Burris, Fixed magnification of 5X

The reticle image is etched into a lens inside the scope. The advantage of this over a “Red Dot” site is that if the battery goes flat there is still a sight picture to use for aiming. The one scope that does not use batteries is the Trijicon ACOG series of scopes. The ACOG sight is the gold standard. That all other prism scopes are compared to this standard.

Prism scope
The Reticle ecthed onto the lens reticle with no power on the left, Red center, and Green on the right. All through the same scope.

The Trijicon scope uses a fiber optic placed on top of the scope. The fiber optic pulls in all available ambient light which illuminates the reticle. This feature works in both day and night time. As you can imagine it is also the most expensive prism scope. But you get what you pay for😊

Acog for AR sights
ACOG sight sitting on top of and AR15

Advantages of the prism AR 15 sights

  • Sights are magnified. This improves the medium to medium long range shots.
  • The sight can work with or without batteries.
  • Large choice of available reticles. Reticles are available in different calibers and shapes. This gives the shooter a lot of choices when buying this type of scope
  • Scopes will usually have predetermined hold overs. Allows for quicker shots at varying ranges
We own and use this Sight
Trijicon ACOG Sights

Trijicon is the Gold standard of Prism sights. Their glass is super clear and you never need batteries

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Disadvantages of the Prism AR15 Sights

  • Sights are harder to use at close ranges. Though not impossible focus at very close ranges can be an issue.
  • Batteries can go flat. Unlike a red dot sight, you will still have an etched reticle to use. However, if shooting at night the reticle will be very hard to see.
  • Prism sights are bulky. The size of the sight is greatly increased. When compared to a red dot or iron sight.
  • The cost of the site is usually higher. There are cheaper versions available of prism type scopes. However, be prepared to pay a premium for an ACOG sight
  • Limited sight positioning on the rail. The prism sight will need to be given the proper eye relief so that the shooter can see through the scope.
  • Magnification and focus are fixed. This means that the scope will not be good at all ranges
AR 15 Prism Scopes
$100 - $500

Prism scopes are a fixed magnification scope. They are a perfect match with the AR 15 Rifle

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Telescopic AR 15 Sights

Telescopic or variable power scopes are generally used more when a rifle is going to be shooting further. One of the biggest things I see shooters do when using this type of AR 15 sights is to buy something with too much power. The effective range of the AR-15 rifle is not that great. Unless you are using a longer, and heavier target barrel. Realistically the maximum effective range should be kept at 300 to 400 yards. Yes, the rifle will shoot further. The problem is by the time the bullet reaches its target it has lost most of its energy and is ineffectual in taking down the target.

ar 15 with Vortex sights
1 x 8 Vortex Scope on an AR 15

When buying a scope that has a large magnification it will only narrow your field of view as well as take longer to acquire a target. Unless you planning to use your rifle as a long-range shooter, and you have the barrel for it, you will be much better served by a lower-powered scope. I would recommend a no higher than 1 X 8 Powered scope for most shooters.

There is also a large selection of reticles, scope powers, and sizes available. Telescopic scopes can also have illuminated reticles. This will make the scope more flexible and usable in low light conditions.

Advantages of a telescopic sight

  • Variable power adjustments. This means the shooter can dial in for longer shots and out for closer shots.
  • Adjustable focus or parallax. Allows the shooter to focus clearly on the target
  • Reticles can be used for ranging. Scopes set with MRad or MOA reticles can be used to calculate range to target
  • Bullet drop information can be used in hold overs. Using specific known bullet drop data will allow the shooter to make accurate hold over shots.
  • Very accurate through most ranges. Except for the very close ranges where the focus may not be great.
Great Value
Primary Arms 1-6x24mm SFP Gen III
$289 - $399

Scope offers multiple reticles to choose from and is great value for the money

Compare at Optics Planet Compare At Amazon
Prices correct at the time of publishing

Disadvantages of a telescopic scope

  • Close Range Shots can be harder. Though not impossible the shooter may have focus issues and will have to hold under for accurate shots at close range.
  • Telescopic sights require specific eye reliefs. A telescopic scope is limited to where it can be mounted on the rifle.
  • The field of view can be limiting. Depending on the power the sight is set at the field of view can be small making it harder to find a target.
  • Batteries can go flat. This will only limit visibility at night

So, what does it all mean

Now that we have gone through all the AR 15 sights, now its time to choose. To help I have created this quick chart. Choices are numbered in order of preference.

AR 15 Pistols

  1. Reflex Sights are going to be the best choice

AR 15 Rifle used mainly for zero to 100 yards

  1. Reflex or hologram
  2. Iron Sights

AR 15 Rifle used between 100 to 300 yards

  1. Telescopic Sight
  2. Prism Sight
  3. Holographic sight
  4. Iron sights

AR 15 rifle used from 300 Yards and up

  1. Telescopic Sight

Conclusion

As you can see there is no perfect site for all applications. You can also see that there are some overlaps in usage. Just choose the best sight platform for your application. Be realistic with your intended shooting habits as well. All too often I see rifle with a really fancy high powered scope on it with all the bells and whistles attached and yet the shooter never goes beyond a 100 yards.

A quick word on bullet drop reticles that come preloaded in a lot of scopes. Do not place a lot of trust in these measurements. Not that they are not accurate for what they say. Where problems can arise is differences in ammunition and altitude can make these hold overs in accurate. So, use pre-built hold overs knowing that you will be in the general area just not maybe right on center.

Be Safe and Shoot often

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Big Dawg Targets 250 Target Roll - 3" Inch Adhesive Splatter Targe
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splatter targets are a great way to improve your shooting day. They offer immediate feedback and you can easily see your hits all the way out to 300 yards.

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2 Responses

  1. This article is right on the money! A very good article that should be expanded upon for even more referencing for new shooters to help them when picking a sight or optic. It is easy to understand what the author is saying. A great writing job! Keep up the good work!

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