For many, the progression of guns begins with a .22 rimfire, then moves to a shotgun and bolt-action rifle. For some folks, this gun evolution reaches its zenith with a semi-automatic rifle.
As you may already know, both bolt-action and semi-automatic rifles began their lives as infantry weapons for militaries. Later they were altered a bit for sporting and hunting use by civilians back home.
The traditional bolt-action rifle is typically considered more accurate and reliable than a semi-automatic. For decades, that was a factor of crucial importance for making a decision in which type of the gun to invest. But the choice of firearms – particular rifles - tends to follow trends.
So right now, besides the bolt-action guns, others that are similar to military-style rifles are also popular, especially with soldiers returning from overseas. And the sales leader among modern semi-automatics is undoubtedly the AR-15 series. According to the National Shooting Sports Federation, around 5 million Americans own some version of an AR-15.
When it first appeared, the AR-15 was widely criticized in gun magazines and the popular press for being unreliable and having mediocre accuracy. However, fantastic developments in AR design have occupied the gun public’s interest over the last few decades. And AR reliability and accuracy have improved almost beyond recognition.
When the law-abiding citizen purchases a semi-automatic rifle, naturally he wants to know how to make the most out of the weapon. There are thousands of options for AR-15 improvements on the marketplace. But a primary upgrade for your AR, no matter its intended use, will definitely include the installation of a sight.
Why optics? On the one hand, these accessories allow us to see targets more clearly. But another reason lies in simplicity - it’s much easier to learn to shoot with a scope than with iron sights. Compared to the complexity of lining up the three elements with metallic sight – a rear sight with the front sight and target, using a riflescope you only have to line up crosshairs with your target.
In order to maximize the platform's accuracy, most firearm enthusiasts use some optical sighting device. The options for AR-15 rifle platform can be a little overwhelming and confusing, so we compose this guide to help you to select the ideal scope for your particular needs.
What’s the Best AR-15 Scope?
Let’s be upfront here: we’re not going to answer that question right away. Together we need to look a lot more deeply.
The AR-15 was originally designed as a weapon of war, but as a modular weapons platform it can be scoped and customized for a whole range of purposes. It could be adapted for varmint hunting, big game hunting, long-range precision shooting, home defense, close-quarters combat and informal shooting and plinking. As we can see, each of these applications, ranging from small pest control to taking out 500-pound feral hogs to urban combat, requires different optics performances to enable successful rifle engagement.
Once you have decided why you need a scope, you have to think about what your average distances will be. Each of the examples we gave calls for different features and performances. There are areas where you can make a compromise, of course. For instance, shooting varmints and big game calls for a powerful, dual-purpose, variable scope in the 3-12x or 4-16x range with a big bell.
A larger objective bell offers a great image in low-light conditions when you’re after moving varmints. This lets you stay out longer after sunset when many of these critters come out of their dens. But you’ll also be able to target larger prey from 400 yards away.
Home defense and close-quarters combat may require entirely different types of optical devices as magnification is less critical and a larger field of view is vital. For that kind of purpose, you might want to look at riflescopes that have lower power, such as the 2-7x or 1-4x, or red dots and holographic scopes.
What are the Factors That Go into Choosing a Scope
Let’s go into a bit more detail at what you need to consider in choosing a scope.
As we’ve said, the AR platform has the near-infinite number of applications with diverse demands. So there are many factors a scope buyer should consider to harmonize optics with an intended mission.
While many AR fans already realize that more magnification is not always better, it’s good to start by saying it again. It all depends on how you’ll use the scope and rifle. And too much can really be a bad thing in this case.
Our first principle is that below 10x magnification is the best for off-hand shooting or following targets. It’s generally strong enough for most recreational hunters and basic target shooters.
At the opposite end of the spectrum, hunting in large open spaces and long range shooting can call for a high-powered 12x, 24x or even 40x magnification telescopic sights. In those case, you probably need a supported position, such as prone or bench shooting.
In real-life situations, that means that hunter in the woods would have a very hard time making a shot with a 32x scope. On the other hand, a bench rest shooter would be under-equipped with a 3-9x scope for a target at 1000 yards.
Also, many shooters use a red-dot for close-range shooting. However, many knowledgeable shooters prefer a low magnification scope of 1x-4x in power for those situations. Without magnification, these scopes can be used like dot- and reflect-style sights. But they can also give you extra magnification at mid-range for taking 100-300 meter shots.
Field Of View
The field of view (FOV) is tightly linked with scope magnification, and you always trade viewable area for magnification. Practically, a low-power scope allows a wide field of view, which is vital if your targets are going to be moving or if you have to fire faster follow-up shots.
Also scopes using a higher level of magnification would have the darker target picture due to the amount of light that can pass through it. Otherwise, the rule of thumb is that larger objective lenses and higher diameter tubes (30 or 34mm) allow more light to enter the scope, thus making the image brighter.
The exit pupil relates to how much light some scope gathers. It’s calculated simply by dividing the objective lens diameter by the magnification. For example, in case of a fixed powered 7x56 riflescope, the exit pupil is 8mm. That is, 56 divided by 7. That gives you a good exit pupil for low-light conditions, where the minimum is 4 mm - so this would work well!
Of course, there are the trade-offs in performance. Since our eye`s pupil expands in low-light conditions, that means we will need a bigger exit pupil to provide an appropriate amount of light.
After choosing the optics and the variable power range, a customer has to select from the variety of reticles offered by the manufacturers. There are dozens of different reticle patterns on the market today, from simple crosshairs through center dots all the way to Christmas-tree style reticles and complex grid patterns.
The average shooter doesn’t need these complicated reticles. Plus, more often than not with hunting optics, keeping it simple is the best way to go.
The three most common types of reticle are the Duplex, BDC, and the Mil-Dot. The Duplex and its variations such as the German No. 4 are simple and straightforward reticles that do what they are designed to do – draw your eye to the center.
Another type of hunter reticle incorporates bullet-drop compensation data on the lens, and they are appropriately called Bullet Drop Compensating (BDC) Reticles. Their design is suited explicitly for common calibers of the AR, and these reticles would be enough for that 400-yard shot.
Finally, the Mil-Dot is tactical-style graduated reticle better suited as a range-finding aid. Generally, it is intended for special-purpose military and law-enforcement use.
One of the leading improvements of recent years is the illuminated reticle that provides shooters with fast target acquisition in lower light and against tangled backgrounds. The lighted thin crosshairs are perfect for improving visibility in day or nighttime use. But inexpensive versions feature reticles that are too bright and ruin any low light capabilities your eyes have developed. Be on the lookout for this if you’re buying a scope with illuminated reticles!
SFP vs. FFP Reticles
Another point to consider is the focal plane. This refers to different positions for the reticle within the scope. The majority of modern scopes have Second Focal Plane (SFP) reticles. These stay the same size in relation to the overall image size, allowing for a further magnification. In other words, the reticle doesn’t get magnified when everything else does.
Scopes using the second focal plane are useful in low-light environments, which limits their usability. But when used with a BDC reticle, they will need to be cranked to maximum magnification for their reticles to be utilized fully.
On the other hand, the size of the First Focal Plane reticle scales up and down as the magnification changes. The front focal plane is used primarily for tactical purpose because you can use the reticle at any power level and keep accurate measurement markings. The first-plane reticle is also good for long-range hunting since it enables accurate shots at multiple magnifications. Today high-end optics manufacturers are switching to the front focal plane models as they clearly surpass their predecessors.
Fog, Water and Shock Resistance
For using the scope in harsh weather, the optics have to be fog proof, waterproof and shockproof. This can be achieved with the well-built seal on the outer lenses paired with multiple coating layers on all air-to-glass surfaces. Today, with modern technology, purging scopes with nitrogen or argon is almost a standard process. Having these resistances should almost go without saying.
The mirage effect is the optical distortion caused by heat waves rising from the overheated rifle barrel directly in front of the scope. Many benchrest shooters experience it especially at higher magnification levels. Actually, the mirage at just 100 yards can become surprisingly distracting and cause misses. As the simple and cheap solution, many shooters use a mirror shield that deflects image-distorting heat waves that come off a hot barrel after multiple shots.
Elevation And Windage Adjustment
For long-range shooters, rapid adjustment of elevation and windage is of vital concerns. Nowadays a favorite choice is “tactical”-style turrets for quick tuning and 30-mm tube scopes since they offer more internal adjustment range than a standard 1-inch scope (for the metrically challenged, 30 mm is almost 1.2 inches).
Nevertheless, the right scope for the hunting will allow for pinpoint accuracy with little to no adjustments, so you should avoid over-adjustment. It can cause more issues than any other problem. Plus, while the ability to make adjustments is good, shooters have to make sure they do not dislodge the turrets, or their shots will be off.
Different Types of AR15 scopes
Now let’s have a look at some general types of scopes that are available.
Despite the preconceptions of many, most shooting scenarios can be handled with zero magnification. Red-dot sights featuring an illuminated dot on top of the picture are a good choice. In particular, if you will frequently be shooting moving targets, you should consider the red/green dot with its unlimited field of view.
Actually, the red dot sights are not scopes. However, they are used for the same reason as your iron sights. So you should also keep backup iron sights on the off-chance that the red dot sight fails. There are two different types of these sights, Red Dot Sight (Reflex) and Holographic Sights. There are many red dots explicitly built for AR rifles.
Suggested: Burris - Fastfire III Red Dot Reflex Sight
Night vision scopes work predominantly in the infrared spectrum as light-enhancement devices. When equipped with one or more reticle pattern, night vision rifle scopes are great with any AR rifle. They help provide reliable shots on predators or wild hogs in deep dark.
Due to industry development, night vision optics are classified into a few quality levels, ranging from Generation 1 to Generation 4 (also known as Gen 3 FLAG). The newest, Generation 3 and Gen 4, offer extended use and excellent light intensification. But they can be very expensive and out of reach for a lot of hunters. As with most things in life, you should choose the cheapest item that still satisfies your needs. In that way, Gen 1 and Gen 1+ night vision scopes offer shooting range from 70-150 yards. They provide superb image quality at a (relatively) meager price.
Suggested: Armasight Vulcan 4.5X 3P MG
High magnification is a good option for specific applications. But for some situations, it could be overkill, especially if you end up needing to make a follow-up shot. A smaller and lightweight scope falls into a special category.
These low-power scopes are more popular and find wider use in other parts of the world. But in the United States the 1-4x scopes are considered somewhat specialized tools and almost strictly in the realm of short to medium-range autoloaders such as the AR-15.
1-4x or 1-6x scopes offer little magnification and are commonly used for fast target acquisition, firing at short distances and firing at high rates. By starting at 1x, a shooter has the choice to use their scope like a Red Dot sight for instinctive, split-second, aiming precision. Modest levels of magnification up to 4x provide more than enough power to shoot a few hundred yards accurately.
Suggested: Leupold VX-2 1-4×20
Long Range Scopes
While the majority of hunting scopes cater to the mainstream huntsman, long-range optics offer a certain amount of elitism and specialty. The same goes for an AR-15 or AR-10`s long-range riflescope. When utilized in the right hands with skill, ethics, and the proper load, they can shoot precisely at distances beyond 500 yards.
Just as a note, an AR-10-style rifle is an excellent Big Game and predator-hunting tool if you use the right caliber. But beside the right caliber, you’ll need superior optics and range-finding equipment, too.
Magnification level is a significant aspect of this optics niche. Some shooters divide long-range hunting and long-range target shooting scopes. Hunting scopes include 4-16X, 5-20X, 5.5-22, or the 6-24X power. Target scopes use 18x, 36x and even 40x for long-range shooting.
Magnification is not the only essential feature to get you out to those long-range distances. Additional features include a full-internal adjustment range with a ballistic turret and parallax adjustment. Further, long-range shooters prefer a large, 56mm scope bell with FFP and the ballistic reticles like BDC, Mil-Dot or Christmas-Tree Reticles.
Long-range shooting implies fully multi-coated lens and superb, crystal clear glass, and this, in turn, means that long-range hardware is more costly than standard riflescopes. Of course you always have to consider your budget, but stick with a quality brand that pumps out the exceptional glass. You may end up investing more in your scope than in your rifle itself, which is not unusual. Some people spend three times as far on the glass.
Suggested: Vortex Optics Viper 6.5-20x50
So What Do I Need For My Intended Use?
As previously mentioned, there are different needs for different shooters. Hunters do not need the same precision as target shooters. But the AR-15 is one of the most versatile guns on the market. When a sportsman pairs it with an appropriate scope, he makes it an accurate and efficient machine to take down game with as little pain and suffering as possible. You can read our AR-15 scopes for hunting buyers guide here
For deer, caliber is essential and some of the medium-sized cartridges are a good choice. Hunting equipment depends on the particular species life environment and weather conditions. Since deer are often in wooded areas, your range is going to be short. That means we don’t need the most powerful lenses available. Instead a versatile and adjustable riflescope with low-to-mid magnification and a wide field of vision at 100 yards should cover you.
In short, lean toward a solid build 3-9X scope with sharp 40mm or 50mm objective glasses and duplex reticle, and you will be well-outfitted for next deer season.
Today, blind hunting of varmints is a popular and growing method. But it’s also is one of the most challenging hunting experiences available.
The predators are fast, wary, and intelligent. They are often hunted in low-light conditions in close ranges below 100 yards. On the other hand, varmint hunting can also take you to the plains challenging your shooting capability at small targets from 400 yards away.
An all-purpose variable-power riflescope with a 3-12x range and a wide field of view with a large objective lens - in the 50mm range - should be well-suited for hunting in low ambient light. For this type of hunting, suitable reticles can be as simple as a dot or classic duplex or as complicated as a tactical Christmas tree-styled reticle.
Once again, versatility is the key word in varmint hunting. The right scope can go a long way to evening the odds and ensuring your success.
Big Game Hunting
Unlike punching paper downrange, ethical hunting means the hunter remembers that he’s dealing with a living being. He needs to know about calibers, kill zones and vital organs to bring his prey down efficiently. For instance, the heart and lungs of African Plains Game are far forward compared to the anatomy of their North American or European cousins.
Your AR-15 isn’t your best choice for big game; let’s not make that mistake. But with the right bullet and in limited circumstances it can serve in a pinch.
Big game hunting takes dedication and a level of seriousness. Wit that comes special care in the choice of equipment. The right optics can help properly place your shot, which in turn guarantees or at least increases the chances of a humane kill.
Hunting big game can involve close contact with dangerous species, so using optics with low magnification is common sense. Some experienced hunters recommend the 2-7x power range as one of the best options, with the 3-9x coming in a close second. A 40mm or 42 mm objective lenses is a great choice.
The higher levels of magnification of 7 to 9 are powerful enough for 99% of hunters in the world because the longest shot will be between two and three-hundred yards. Now, if you’re going to switch to a weapon more suitable for regular big game hunting, you’re going to have a bigger bore and fare more recoil. So you’ll want a scope appropriate for that gun, as well, and not whatever you have on your AR-15. The scope construction has to be from one piece tube with generous eye relief to help protect your face from the rifle’s recoil.
Recreational shooting and close-quarters plinking with AR-15 rifles are quite popular. They also don’t require high-end optics. For punching paper and range play at 100 yards the modern sporting rifle owner can pick out a very affordable optic that’s proportional to the little “black rifle” and compact and lightweight as well.
With so many different kinds of AR optics, from red dot reflex and holographic sights for shooting at 25 and 50 yards, to full-sized scopes for 100 yards plinking, you should know that the more you pay, the higher quality you get.
While some red dot sights may provide more-than-adequate clarity and accuracy, the low-powered line of AR-15 optics has gathered a lot of attention in the AR realm. The scopes on the lower end of the magnification scale like 1-4x or 1-6x magnification provide versatility and offer some excellent performance. On 1x power, these compact scopes are almost as fast as a red dot sight. On 4 or 6 power, you still have good target acquisition with enough magnification to be accurate at several hundred yards.
Until now, aficionados in the 3-Gun world have been looking for a red dot or holographic sights. More recently scopes with moderate levels of magnification are becoming more common.
The growing market for low-power scopes offers a vast assortment of telescopic sights with a low-end in the 1x to 2x range. Not long ago a variable optics sporting 1-to-4 power was all the rage. With advancing technology the new "minimum seems to be 1-6x. A few 1-8 X scopes are waiting at the door as the next horizon for 3-gun optics.
With “true” 1x (no magnification) at the low end, these scopes include an illuminated center dot that mimics a red dot sight for speed on close-range targets. An illuminated ballistic reticle allows shooting at mid-range targets.
Of course, a gun that started as military assault rifle also has optics for the tactical use. So it’s perfectly understandable that every tactical rifle enthusiast should be looking at them when buying new optics for a semi-automatic rifle.
Holographic and red dot sights are intended primarily for close-quarter combat. They are often used by military personnel and law enforcement agencies. While the holographic sight has much bigger reticle and wider field of view than a red dot scope, they have no magnification and are much more expensive. Another tactical-style scope is red/green dot sight that is also perfect for snap shooting. It’s great for hunting varmints at close range or training for any urban survival scenario.
Low-powered variable or fix scopes have also gained an incredible amount of popularity within the military and law enforcement as well as civilians arming for home defense. These scopes feature ballistic reticles and are perfect for engaging close-range targets or dangerous game, but they can also be used at longer ranges.
There are many different AR scopes to use in varying scenarios. A basic rule to follow is that scopes from reputable manufacturers are extremely unlikely to have any issues. For most of us, a budget drives most decisions, but you shouldn’t settle for cheap, low-quality scopes that will not last an entire magazine without breaking or losing zero.