The AR-15 Modern Sporting Rifle (MSR) is one of the most popular firearms in the United States today. While it is impossible to know exactly how many of these versatile weapons are owned by civilian shooters, the National Shooting Sports Foundation estimates the number to be approximately 15 million.
No matter how you plan to use your MSR, finding the best AR-15 scope (or other modern optic) will improve your shooting.
Due to their popularity, the AR-15 gets a ton of aftermarket support. If you want a truly customized weapon, the AR-15 is easy to accessorize, and a quality optic should be at the top of your list.
If you aren’t sure what to look for in an optic, we’re here to help. We’re going to walk you through the different types of optics and tell you what they do best. We even share some of our favorite models to get you started.
It doesn’t matter if you use your AR-15 for home defense, hunting wild hogs, running 3 Gun courses, or just for fun. By the end of this article, you’ll be well on your way to finding the perfect optic to match your mission.
Why Your AR-15 Needs an Optic?
One of the reasons the AR-15 gets so much attention is because it’s so easy to shoot. Even inexperienced shooters take naturally to these lightweight, low-recoiling rifles.
A well-built AR-15 can also be insanely accurate. The design lends itself to consistency, and when held in skilled hands, the AR-15 is easily capable of sub MOA groups at 100 yards, even with iron sights.
With the right optic, you can engage targets faster, more accurately, and with less effort. A good optic can also extend your effective shooting range. Accurately hitting deer-sized targets with open sights at 100 yards isn’t out of the question. However, even talented shooters need a scope to accomplish the same feat on smaller targets at greater distances.
Choosing the Best AR-15 Optic
Photo credit: Alice Jones Webb
There are thousands of optics available for the AR-15. With so many options to choose from, it’s easy to feel overwhelmed by the possibilities. Let’s look at the types of optics available to the modern shooter. Once you understand the options and what they do best, it will be much easier to find the best new optic for your AR.
Red Dot Sights
In recent years, “red dot” has become a blanket term for any optic (including reflex, red dots, and holographic sights) that projects a red reticle through the field of view and onto the target. While their general function is the same, some of these sights use vastly different technology.
One of the most popular optic styles for AR-15s, red dot sights are basically electronic sighting systems. Red dots use light emitting diodes (LEDs) to project a dot-shaped aiming point from behind an objective lens covered with a partial mirror coating. The aiming point (which is usually red) is reflected off the back of the objective lens toward the shooter’s eye. To aim, the shooter simply places the red dot over the target and squeezes the trigger.
A red dot sight is helpful when you need to engage close-range targets with speed and accuracy. Red dots are also a great option when encountering multiple or moving targets.
Because red dots are intuitive, they are perfect for home defense weapons. They can help you make fast, accurate shots, even when your shooting skills are handicapped by stress and adrenaline.
Holographic (or holo) sights often get lumped into the same category as red dots. However, holo sights use a series of lasers and mirrors to produce a reticle superimposed over the target.
Where a red dot is reflected back at the shooter’s eye, the holo sight’s reticle appears to float in front of the optic. This allows you to focus on both the target and the reticle at the same time, which is much easier, especially for new or inexperienced shooters.
Since the technology used in holographic sights is more complicated than that used in traditional red dots, holo sights are much more expensive. Expect to spend at least $400 on the cheapest holo sight. However, because these sights are easy to use, highly accurate, and virtually indestructible, many shooters agree they are well worth the investment.
Unlike traditional scopes that use a series of lenses to magnify an image, prism (or prismatic) scopes use a special glass prism. The design makes prism scopes lighter and more compact than a traditional riflescope. Because they are significantly shorter than a traditional scope, prism scopes are a great option for shorter AR-15s, especially those with limited rail space.
Prism scopes usually have a lower, fixed magnification (usually somewhere between 1x and 5x). Although this level is lower than a standard rifle scope, it is still useful for accurate shooting at short to medium ranges (usually out to 600 yards).
Without any moving internal parts, the average prism scope tends to be more durable and reliable than its variable power cousins.
Variable Power Scopes
Well-suited for long range shooting, a variable power scope provides a range of magnification. Because you can zoom in on distant targets, a variable power scope allows you to see more target detail, allowing you to aim more precisely. Often used by hunters and tactical snipers, variable power scopes provide easy adjustments for windage and holdover, a necessity for accurate long range shooting.
The biggest disadvantage to a variable power scope is the size and weight. Scopes with large objective lenses and powerful magnification can add a ton of weight to your rifle. That extra weight negates most of the advantages of a compact, lightweight AR-15.
Some shooters claim a variable power scope on an AR-15 is overkill, especially given the relatively limited effective range of the typical .223 Remington/5.56 NATO chambering. However, as more AR-15s chambered for alternative cartridges (like 6.5mm Grendel and .300 Blackout) emerge, using variable power scopes on modern sporting rifles is beginning to make more sense.
The two numbers preceding the x in a scope’s designation indicate the scope’s magnification range. Bigger numbers before the x mean you can zoom in more on distant targets to see more detail.
In the world of AR-15s, bigger rarely means better. Too much magnification can be more of a hindrance than a help. 1-8x seems to be a sweet spot for AR-15 scopes, providing plenty of versatility for most shooting applications.
If you’re shooting an AR-15 chambered in standard .223/5.56, anything over 9x is probably overkill. However, if your AR is chambered for one of the hotrod alternate cartridges (like .22 Nosler or .224 Valkyrie), a scope with 16x magnification could help you punch bullseyes up to 1000 yards away.
The number that follows the x in the scope’s designation indicates the diameter of the objective lens in millimeters. Generally, a scope with a larger objective lens will transmit more light to your eye, creating a brighter, clearer sight picture, especially in low light conditions.
Even if you plan to hunt coyotes at twilight, an overly large objective lens can prove problematic. A large objective lens makes a scope heavy and bulky, two things that don’t work well on a lightweight, compact AR-15. Anything larger than 40mm is excessive, unless you’re shooting extreme ranges from a bench rest.
FFP versus SFP Scopes
When considering a variable power scope for your AR-15, you’ll need to choose either an FFP or SFP model.
FFP refers to a scope with a reticle located on the first focal plane. The size of the reticle on an FFP scope changes size as the scope is zoomed in or out. The size of the reticle will remain consistent with the size of the target, no matter which magnification level you use.
SFP means the reticle is located on the second focal plane. With an SFP scope, the reticle remains a constant size, no matter what magnification level you dial in.
When using a rangefinding reticle (like a mil dot), an FFP scope will offer accurate ranging, no matter the magnification level. If you are using an SFP scope, the ranging reticle is only accurate at one level of magnification.
If you plan to shoot long-range targets with your AR-15, an FFP scope will allow you to make more accurate shots, no matter what level of magnification you choose to use. However, FFP scopes tend to come with higher price tags.
Best AR-15 Scope on the Market Reviews
1. Vortex Optics Razor HD Gen II 1-6x24mm – Best Variable Power Scope for AR-15
Vortex Optics are well-known for producing high-quality, reliable scopes to fit every budget. We think the Vortex Razor HD Gen II is one of the company’s best offerings. It has quite a fan base, including 3 gun competitors, predator hunters, and recreational shooters.
This LPVO (low power variable optic) is built like an absolute tank. Nearly indestructible, the Razor is o-ring sealed, argon purged, and fully shockproof, waterproof, and fogproof. It is constructed from a solid piece of durable aircraft grade aluminum alloy. It also has a hard anodized exterior finish for extra protection from weather, bumps, and scratches.
The optical quality is some of the best we’ve seen, with high-density, extra-low dispersion glass and lenses that are fully multi-coated. Vortex uses XR plus anti-reflective coatings to maximize light transmission, and the result is bright images with razor sharp edges, even in dim light.
We also love the Razor’s unique JM-1 illuminated center dot reticle. This SFP reticle design promotes rapid, accurate shooting at distances from close range to 600 yards, making it well-suited for 3 gun and most hunting applications.
2. Monstrum 1-4x24mm Alpha Series – Best Budget AR-14 Scope
It’s hard to find an affordable rifle scope with an FFP reticle, but somehow Monstrum made it happen. Priced well under $200, the Monstrum Alpha Series 1-4x riflescope delivers the best bang for buck value of any scope on our list.
This is a high-quality tactical scope, perfect for targets out to 300 yards. It also works well for deer hunting, especially on an AR chambered in something powerful enough to ethically drop whitetails (Think 6.5 Creedmoor).
Monstrum Alpha Series scopes have fully multi-coated lenses that are designed to reduce glare and provide a crystal clear image. They also feature silky, smooth turret adjustments that make precision holdover and windage adjustments a cinch.
Built for rugged shooting conditions, Monstrum Alpha Series scopes are made with sturdy 6061 grade aluminum and feature a military-standard hard anodized outer finish for extra toughness.
3. Trijicon ACOG 4x32mm – Best Tactical Scope for AR-15
The Trijicon ACOG (Advanced Combat Optical Gunsight) is a true battle-proven tactical optic. This is the scope used by the United States Marine Corps on M27 rifles for their Squad DMRs (designated marksman rifle). Designed to help fill the gap between a long range sniper and an infantryman, the ACOG is perfect for medium range shooting.
One of the best fixed power scopes ever designed, the Trijicon ACOG is super rugged. It features a durable housing constructed from forged 7075-T6 aircraft grade aluminum alloy. Although virtually indestructible, the ACOG is still backed by a lifetime warranty.
With relatively short eye relief and a large objective lens, the ACOG has a massive field of view. The reticle is also designed for “both eyes open” shooting, so you retain all your peripheral vision and preserve precious situational awareness.
The scope also features a bright green reticle allowing for easy range estimation out to 800 meters. Plus, it has BDC (bullet drop compensation) marks for standard 5.56/.223 ball ammo.
The Trijicon ACOG offers battery-free illumination. Because the scope is powered by fiber optics and tritium rather than batteries, it makes a great option for an off-grid or SHTF fan scenario.
4. Athlon Optics Midas TSP4 – Best Prism Scope for AR-15
The versatile Midas TSP4 from Athlon Optics is one of the best compact prism scopes currently on the market. It features fully multi-coated lenses that provide bright, crystal clear, glare-free images, even in low light shooting conditions. Plus, the Midas TSP4 offers 3x fixed power magnification, which sits right in the sweet spot for medium to long range AR shooting.
The etched glass BDC reticle remains visible even when the optic isn’t switched on. However, the scope also features multiple illumination settings to maximize reticle visibility in various ambient light environments.
The Midas TSP4 is built to handle rough use in rugged conditions. It is made with a one-piece, heat-treated chassis that is constructed of high-quality aircraft grade aluminum. The body is nitrogen-filled and o-ring sealed to reduce internal moisture and prevent fogging. This tough optic is also waterproof and shockproof.
5. Leupold VX-Freedom 3-9x40mm – Best Hunting Scope
Leupold has some of the best glass quality in the optics industry, and they make their scopes to last a lifetime. We love the Leupold VX-Freedom 3-9×40. This variable power scope has a 3-9x magnification range and an easy-to-use duplex reticle that make it perfect for hunting everything from varmints to whitetails. It’s also priced under $300, so it fits into even the tightest hunting budgets.
Built to withstand the rough conditions hunters often face in the field, the VX-Freedom is 100 percent waterproof, fogproof, and shockproof. It also performs flawlessly at extreme temperatures.
Deer hunters will particularly love Leupold’s patented Twilight Light Management System. This unique system reduces glare and maximizes light transmission, to provide the brightest, clearest images possible. The Twilight Light Management System will also add up to ten extra minutes of clear shooting light at dawn and dusk. This extends your hunting time to include the times when big bucks are most active.
6. Steiner T5Xi 3-15x50mm – Best AR-15 Scope for Long Range
Although the AR-15 isn’t known for its long-range prowess, the rifle is capable of pinging targets beyond 500 yards, especially when chambered for one of the newer hotrod cartridges. If you want to milk every ounce of long range accuracy possible from your AR-15, the Steiner T5Xi will help you do just that.
The Steiner T5Xi riflescope features a unique Special Competition Reticle (SCR). This illuminated, glass-etched FFP reticle provides MOA windage, holdover, and ranging marks. This is a highly detailed reticle pattern designed for serious precision shooting. Mount this on a rifle loaded with quality ammo, and you’ll be driving tacks at impressive distances.
Although this scope is most at home on the target range, Steiner built it tough enough to handle just about anything. The housing is milled from a single piece of solid, high-grade aluminum stock. It is nitrogen-purged, o-ring sealed, and completely fogproof and waterproof. This scope will even work like a charm after being completely submerged under 33 feet of water.
7. EOTECH Vudu 1-6x24mm Riflescope – Best AR-15 1-6x Scope
EOTech’s high-quality holo sights make it easy to fall in love with the company, but their Vudu riflescope definitely seals the deal. Designed for serious 3 Gun competition, this scope feels right at home on your AR-15.
The Vudu features EOTech’s patented Speed Ring reticle. You won’t find this illuminated FFP reticle anywhere else. When used at 1x, the Speed Ring is perfect for CQB. You’ll have a hard time finding a reticle design that allows for faster acquisition of close range targets.
When you zoom in to 6x magnification, this scope provides the crisp resolution and dependable accuracy you need for targets at longer ranges.
The Vudu features crystal clear XC high-density glass, which provides spectacular light transmission for a bright, clear sight picture even in low light.
The Vudu is built to handle rough use in demanding tactical environments. The housing is constructed from a single piece of aircraft-grade aluminum, and it features a hard anodized finish for extra protection from the elements.
8. EOTech Model 512 – Best AR-15 Holographic Scope
Holographic sights and AR-15s go together like peanut butter and jelly. Honestly, it’s like the two were made for each other. EOTech is responsible for introducing holo sights to the firearms world, and their Model 512 is their most popular optic.
The Model 512 features 20 daylight settings. This allows you to easily adjust the reticle brightness to match outside light conditions for enhanced visibility in bright sunlight or dim twilight.
The EOTech Model 512 is compact, lightweight, and super durable. Even if you break the glass, the optic holds its zero and still remains functional. It even offers up to 1000 hours of battery life, which is pretty impressive for a holo sight.
Compared to some of EOTech’s other holographic models, the 512 is a pretty basic, no-frills option. However, the 512 is completely functional and is one of the most affordable optics in the EOTech line-up.
9. Sig Sauer Romeo5 – Best Red Dot for AR-15
Red dots are all the rage in the AR-15 world. Perfect for home defense, tactical applications, and 3 Gun shooting, red dots allow for fast and accurate short to medium range shooting.
Thankfully, you don’t have to drop a ton of cash for a high-quality red dot sight. The Romeo5 from Sig Sauer is one of our favorites, and at just under $200, it is one of the best value optics on our list.
The Romeo5 has a lot to offer for the money. It features a clear, versatile 2 MOA red dot with 10 brightness settings (8 for daylight and 2 for night vision). This allows you to find the perfect setting and maximize reticle visibility for more accurate shooting at any time of the day or night.
Thanks to this red dot’s Motion Activated Illumination, you get an incredible battery life of 40,000 plus hours. This handy function automatically turns the optic on when it detects motion, and then powers down after a period of inactivity. You can literally leave this red dot sight on and never worry about draining the battery. It is guaranteed to be ready to go whenever you are.
10. Aimpoint Patrol Rifle Optic (PRO) – Best Optic for a Short Barrel AR-15
AR-15s seem to be getting shorter and shorter these days, with compact carbines and pistols taking over the AR scene. While these short, lightweight weapons are easy to maneuver and built for CQB, they can still greatly benefit from a quality optic.
The Aimpoint PRO is one of the best-selling red dot optics on the market. Although built for the battlefield (It is literally bombproof!), this rugged little red dot is just as much at home plinking soda cans off backyard fence posts.
It has a crisp, clear 2 MOA red dot reticle with multiple brightness settings. It features six settings for daytime shooting and four settings compatible with all generations of night vision, making this optic perfect for after-dark maneuvers.
The Aimpoint PRO is virtually parallax free and provides absolute co-witness with fixed front sight.
It comes with a 3-volt lithium battery that offers an impressive 30,000 hours of operation. You can turn the Aimpoint PRO on, leave it on, and not have to change the batteries for a full three years.
11. Bushnell Trophy TRS-25 – Best Red Dot for Under $100
There are some shooters who believe you can’t find a good AR-15 optic for under $100. Those shooters are wrong.
A great option for the shooter on a shoestring budget, the Bushnell Trophy TRS-25 gives you tons of quality and performance, and you won’t need to drop a ton of cash to get it.
Surprisingly solid for an optic in this price range, the Trophy TRS-25 is o-ring sealed and nitrogen purged. This construction provides real fogproof and waterproof performance, even when the humidity runs high. The housing on the Trophy TRS-25 is also shockproof, so it can easily survive bumps, drops, and bounces, and still hold its zero.
Lightweight and compact, this awesome red dot won’t take up a lot of real estate on your rail. It’s also incredibly versatile, so if you want an affordable optic for range shooting, 3 Gun, or even hunting, this is a great tool for the job.
12. ATN ThOR HD 640 Smart – Best AR-15 Thermal Scope
The AR-15 is perfect for hog and coyote hunting, but the rifle becomes even more effective when paired with this thermal scope from ATN. ATN makes some of the best digital optics on the market. Catering to after-dark hunters, ATN understands exactly what they need from a thermal optic.
The ThOR HD 640 has a highly sensitive thermal sensor that catches heat from your target and translates it into a clear digital image. It uses an Obsidian T II thermal core, which is basically a high-tech specialized onboard computer.
Far more than just a thermal optic, the ThOR 640 also provides an onboard rangefinder. It also features GPS location, so you can always find your way to and from your favorite hunting spots.
Our favorite feature is the ThOR’s recoil activated video (RAV) and Wi-Fi streaming, which automatically captures the moments immediately before and after your shot. You can even instantly share all the hunting excitement with your friends and family.
13. ATN X-Sight 4K Pro Smart Day/Night – Best Night Vision Scope for AR-15
The ATN X-Sight uses digital technology to help you see in the dark. Unlike standard night vision technology that can only be used after the sun goes down, you can use the X-Sight Pro at night or in broad daylight. This allows you to transition seamlessly from daytime to nighttime shooting with one awesome optic.
Built to meet all your predator hunting needs, the ATN X-Sight Pro has adjustable magnification (5-20x), so you can easily zoom in on distant game to make precision shots. It also has a detailed onboard ballistic calculator that factors range, wind, and angle to target, and then calculates the perfect trajectory. The optic even accounts for temperature and humidity. Plus, it stores multiple weapon profiles, so you make precision shots every single time.
In addition to being an awesome riflescope, the X-Sight Pro features a 4K video recorder and a built-in HD screen. With recoil activated recording, you never have to worry about forgetting to switch on your recording device at a critical moment in your hunt.
14. Magpul Gen 2 BUIS – Best AR-15 Back-Up Iron Sights
Although back up iron sights (BUIS) definitely don’t qualify as an optic, no discussion of AR-15 sighting systems would be complete without giving them at least a mention. BUIS are crucial to have in case your primary optic breaks, runs out of battery power, or fails in some other way.
Magpul Gen 2 BUIS are the best of the best. Although they are made of durable polymer, they are still considered “iron sights”. Polymer is much lighter than metal, and helps keep these sights ultra lightweight without sacrificing durability.
The spring-loaded design allows these instantly flip up for fast and easy access. When not in use, they fold down out of the way so they won’t interfere with your primary optic.
The flat top on most modern AR-15s just begs for a quality optic. These weapons look almost naked without one. While iron sights are durable and dependable, an optic can help take your shooting skills to the next level.
However, even the best AR-15 scope is no substitute for good old-fashioned practice. An optic, no matter how fancy or expensive, won’t magically make you an expert marksman. Optics only enhance your shooting skills; they don’t replace them. The best way to become a better shooter is to spend time sending lead downrange. That’s true, no matter what optic your AR-15 is wearing.