Gun Gods: Guns, Ammo and the Second Amendment

A Guide to Choosing the Best AR15 Scope

The AR15 / M-16, originally designed to replace the aging M1 Garand / M-14, is a truly versatile weapon: from competitive shooting / hunting, to keeping farmland clean of rodents and predators, to self-defense, this rifle can handle it all – provided it is setup correctly.

One of the most important determinants of how well an AR-15 will fit its intended role is the aiming mechanism: the stock iron sights may work fine for blunt CQC scenarios, but if you’re interested in calculated, tactical shots, you’ll have to spend some dough on an aftermarket scope.

Best Scope for AR15 Comparisons



Reticle Type


Our Ratings

Nikon P-223

1.1 lbs

BDC 600

Limited Lifetime

rifle scope review of the vortex viper

Weaver Tactical 1-5x 24mm

14.4 ounces

CIRT / illuminated

Limited Lifetime

Top rifle scope

Leupold VX-1 3-9x40

11.2 ounces


Full Lifetime

Top rifle scope

UTG 3-12X44

1.4 pounds


Limited Lifetime

Top rifle scope

Nikon M-223

19.93 ounces

BDC 600

Limited Lifetime

Problem is, the market is absolutely brimming with sighting utilities for AR-15s – and in order to find the best AR15 scope for yourself, you’ll either have to be a veteran marksman, or someone who’s willing to do painstaking research. I started out as the latter, but now I’ve put my knowledge into this guide to spare you the trouble, so you can get straight to the part where you purchase the right scope for your AR-15 and get on with using it!

Do you need a scope for your AR15?

Before you delve into the guide proper, make sure that it is indeed a scope you need for your rifle. Here are a couple of examples where you’ll be fine using alternatives:

Self Defense:

In the sub-50 yard range, if you’ve got decent eyesight, you’ll be fine using illuminated iron sights that come with your rifle. The target will be quite visible without any magnification – in fact, a magnified optic may even reduce your field of vision.

Besides, in a self-defense situation, you’ll likely be too caught up in the heat of the moment to aim precisely and will probably be shooting from the hip most of the time.

Close Range Hunting:

When you’re hunting close range however, you require a degree of accuracy (even though the zoom is an arbitrary choice here). Lots of hunters prefer red-dot or reflex sights at this range with 1x magnification setting (i.e. no zoom at all), since it allows for the best possible precision without restricting their view or requiring extra focusing / adjustment.

However, for medium to long range shooting applications such as mainstream hunting, competitive shooting, varmint clearing on big farmsteads and so on, there’s no better sight-assistance than a magnified rifle scope.

Factors to Consider when Purchasing an AR-15 scope

Magnification range & objective lens diameter

One of the most important characteristics of a scope is the range of zooming powers it offers – for instance a typical AR15 hunting scope may have a 3-9x 32mm specification. The 2-9x indicates that the scope is able to provide you visual magnification from 3x actual size through 9x actual size, usually in increments of 1x.

32mm indicates the diameter of the objective lens, which is a measure of how much light the scope lets in. Generally speaking, the greater the objective lens of the scope, the clearer the picture you’ll get – however, this will also make the scope tougher to manage.

As an illustration, 32mm is a relatively small value which minimal light transmission but is also the lightest, so it is suitable for daytime shooting applications only. More sophisticated scopes can have sizes as large as 75mm, but those are for shooting targets at extreme ranges, in dimly lit situations and are a bit uncomfortable to aim with.

Light transmission

When you’re operating at higher mag powers, light transmission becomes critical to ensuring a clear and crisp image of the target – besides the objective diameter discussed above, light transmission is also affected by the type of optic coating used on the lens.

The best AR15 scopes will have fully multi-coated optics that provide maximum light transmission even in sunset / sunrise conditions when the ambient light is dim.

Field of View

FOV shares an inverse relationship with mag power – the highest mag power will allow you to see the smallest picture through the scope. If you want to do long range hunting, but want a decent view of the hunting ground too, you’ll need to invest in a scope that has a large objective diameter e.g. 40 mm+, so the view is wide even at the highest zoom setting.


AR15 rifle scopes come with several different types of reticles, each of which is suited towards specific application(s):

  • Crosshair
  • Duplex
  • Mil dot
  • BDC

The classic crosshair reticle can be either thick or fine, and is the one preferred by purist marksmen who want to do range estimation and compensation without any aid.

Note that only first focal plane scopes allow you to use compensation markings for all mag settings – however, these are more expensive; the more common second focal plane scopes’ reticles are only calibrated for use at a particular magnification, typically the highest.

Windage and elevation adjustment

These knobs are a staple in all scopes, and allow the shooter to compensate for horizontal and vertical deviations (due to wind, gravity, Coriolis Effect etc.) respectively. Normally, these adjustment knobs are graduated in minutes of angle (normally ¼ MOA), although some also use mil radian markings.

If you’ll be using the scope in dense bush land, the knobs may snag on branches and be an inconvenience. However, they’re imperative for shooting at extended ranges if you want accurate shots. You may want to consider exposed turrets as opposed to capped turrets for such environments to minimize the space occupied by the scope and thereby reduce the chance of snagging.

To allow for convenient operation, modern scopes come equipped with turrets that can be adjusted just by using your fingers. They should also be spring loaded in order to keep them from moving accidentally due to the impact of a shot. An additional feature to look out for is a zero reset – this means you’ll be able to manually specify the default windage / elevation settings of your scope, so you can quickly dial back to them on the fly.

Certain AR-15 scopes come with ballistic turrets – these adjustment knobs have markings in meters / yards as well as the standard MOA calibrations. These allow you to quickly adjust your scope to shoot a target at a known distance. On the flipside, they’re oversized to allow for the extra markings, and are also more expensive and complex to set up.

Parallax adjustment

Parallax occurs when the focal point of the scope does not lie on the reticle: when you move your eye (without moving your head) to look at a different portion of your target through the scope, you may notice that the target moves – this is an indicator of a parallax error.

Decent rifle scopes come with dedicated parallax adjustment knobs that allow you to set it straight in the field – if you choose to invest in a product that doesn’t have one though, you’ll have to visit a shooting range to get rid of the parallax!

Main tube diameter

Rifle scopes come in either 1 inch or 30mm main tube diameter variations. For most applications, a one inch tube dia. will suffice – however if you want more flexible internal adjustment range, go for the 30mm option.

Ruggedness and sealing

Unless you plan to restrict yourself to indoor shooting ranges only, you’ll undoubtedly be using your AR15 in situations where it can get messy. That’s why it’s important to find a scope that is nitrogen filled, and O-ring sealed to eliminate fogging or moisture accumulation in the lens.

The lenses should have a scratch resistant coating on their exterior surface and the body should have a corrosion resistant paint to keep it in tip-top condition for the longest possible duration of time.

Top Rated AR15 Scope Reviews

Nikon P-223 3-9x 40 Matte BDC 600

  • Zoom Range: 3-9x
  • Objective Diameter: 40mm
  • Tube Diameter: 1”
  • Parallax setting: fixed
  • Quoted Minimum Eye Relief: 3.6 in

The P-223 BDC 600 scope is an affordable yet essentially robust solution from Nikon that is geared towards medium range marksmen in need of a tactical solution.

Featuring the manufacturer’s expected high end multi-coated lenses, the scope is able to yield a very efficient 98% light transmission, so you can use this scope confidently in dimly lit situations – this would not have been achievable with the 40mm objective diameter alone.

The maximum zoom of 9x is obviously suited for medium range encounters, but the lower mag values definitely let you use it at somewhat closer ranges too.

The scope’s BDC reticle has been optimized for use with 55 grain polymer tip 5.56 NATO / .223 Remington caliber ammo – the most commonly used AR15 caliber, mind you – with aiming points from 100 to 600 yards to help you compensate for bullet drop. Bear in mind though, that this is a second focal plane scope, so the BDC markings are only useful for the maximum zoom setting.

However, if you’re using a different caliber or need to fine-tune the configuration, you can do so quite easily thanks to Nikon’s Spot On Ballistic Program – all you need to do is supply the app the relevant parameters, and it will calculate the adjustments you need to make in order to line up the perfect shot.

Speaking of adjustments, the scope offers 80 MOA of internal adjustment through its windage and elevation knobs graduated in ¼ MOA clicks. These knobs keep their setting even after recoil from a powerful discharge. You can also quickly dial to zero by pulling up the spring loaded knobs and rotating them back at any time in the field.

The P-223 offers 3.6’’ of consistent eye relief, allowing you to utilize high recoil bullets or shoot from unusual angles without fear of hurting your brow. The scope is both waterproof and fogproof, and features an understated matte finish so it can be camouflaged easily in sunlit conditions outdoors.

As budget scopes go, this isn’t a bad bargain, but it does have a couple of nagging issues: first, there’s inconsistent build quality and performance – complaints about loose adjustment knobs, shoddy focusing and weakly fixed lenses. Fortunately, the scope comes with a lifetime warranty that you can use to get a replacement in these situations.

Secondly, there’s the fact that the parallax is fixed at 100 yards and there’s no adjustment knob for correcting it at higher ranges, requiring you to be quite precise in your aiming. This issue stems from the fact that this is a scope geared towards budget bound shooters – there’s really no fixing it at this price-range – if you want better quality, you’ll have to loosen the purse strings!

What We Liked

  • Affordable yet robustly built.
  • Excellent light transmission.
  • BDC reticle greatly eases range estimation and aiming.
  • Nikon Spot-On app lets you set up this scope for any AR-15 shooting configuration.
  • Lifetime warranty.

What We Didn't

  • Second focal plane lens restricts the usefulness of BDC reticle.
  • QC concerns.
  • Parallax fixed at 100 yards.

Weaver Tactical 1-5x 24mm Illuminated Intermediate Range Scope

  • Zoom Range: 1-5x
  • Objective Diameter: 24mm
  • Tube Diameter: 30mm
  • Parallax setting: fixed
  • Quoted Minimum Eye Relief: 4.25 in

If you’ll be using your AR15 for CQB purposes, this first focal scope is hard to pass on with its true 1x zoom setting and illuminated CIRT reticle.

To make the most out of its small 24mm objective, the manufacturer uses fully multi-coated lenses to ensure maximum light transmission; as such, the scope has received praise from marksmen on the clarity of its view, even when the sun goes down. The lenses have been given an extra-hard exterior coating to minimize scratching and other damage in the field.

This is a close quarters AR15 optic with its 1-5x zoom range, but within the 100 yard mark, it can really find its mark thanks to the proprietary CIRT illuminated reticle it incorporates. The glass-etched CIRT reticle features markings on its posts that will help you estimate range and compensate for bullet drop and wind speed.

While the product lacks an adjustable parallax, this shouldn’t be much of a problem considering that you’ll be using it in the sub-100 yard range in all likelihood.

Since the reticle is illuminated, you can use it in incredibly dim light as well – but I’ll recommend you stick with the red color setting, since the green can be a bit too bright sometimes. The reticle is first focal plane, so it changes its size with the zoom adjustment, going from a thick dot at the highest setting to a fine speck at the lowest – thereby allowing you to aim precisely at all zoom settings.

The scope has easy to use adjustment turrets, which can be reset back to zero simply by pulling them up, dialing back and then pushing them down. The internal adjustment range is a generous 95 MOA, with 1/4 MOA graduations on the knobs. The only snag is that the zero set does not have a positive engagement, so you can’t be sure if you reached perfect zero, or if the zero has moved afterwards.

With a 4.25” eye-relief, you can use this product safely even with high-recoil setups without fear of injury, and it sports a high-end 30mm one-piece tube design for maximum structural integrity. Furthermore, it is shockproof, fogproof and waterproof, and comes with a limited lifetime warranty in case a problem does develop (I haven’t come across any complaints yet).

The only problem with this otherwise exceptional product is its beefy price-tag, which put it out of the reach of budget restricted riflemen. However, as a high end, close quarter tactical solution, this is a near-flawless product.

What We Liked

  • Sturdy one-piece construction.
  • First focal plane, illuminated CIRT range estimating reticle.
  • Excellent light transmission.
  • Generous internal adjustment.
  • Lots of eye relief.

What We Didn't

  • Zero set does not have a click indicator.
  • Expensive.

Leupold VX-1 3-9x40 Matte Black, Duplex

  • Zoom Range: 3-9x
  • Objective Diameter: 40mm
  • Tube Diameter: 1”
  • Parallax setting: fixed
  • Quoted Minimum Eye Relief: 3.7 in

The VX-1 3-9x40 is a classic product from a manufacturer with a long history in ranged optics, and yields surprisingly strong core performance at a remarkably affordable price.

Crafted from aircraft grade aluminum, the scope’s lightweight yet durable body has been o-ring sealed and nitrogen filled to ensure waterproofing and fog-proofing. It is evident that the 3-9x 40mm optic configuration is meant for medium range hunting / competition situations, but the eyebox does make target acquisition at this range quite an enjoyable experience.

Featuring Leupold’s proprietary Quantum Optical technology, the scope utilizes multi-coated, lead-free glass that transmits up to 92% of incident light, so you’ll be able to get a crisp picture regardless of external lighting conditions. The spacious eyebox ensures a minimum 3.7” of eye-relief (at 9x magnification), so there’s no concern about brow injury from a massive recoil.

The scope’s traditional duplex reticle will appeal to purists who are not interested in overly complex range estimation markings. Note that this is a second focal plane scope, but thanks to the simple duplex reticle, you won’t be as distracted by the lack of variation in the reticle size as you change the mag values. The reticle itself has been optimized for use with the popular 5.56 NATO / .223 Remington ammo caliber.

The 52 MOA of internal adjustment is a bit stingy: while the turrets are easy to adjust and ensure repeatability, the adjustment range itself is not on par with what some of the competition is offering, and in extreme range situations, may require you to compensate manually.

However, it is quite pleasing that the product does not lack in build quality – there have been no complaints pertaining to unreliable adjustment settings, or lenses coming loose with this product, and this is quite a feat given the low price of the scope. Furthermore, it comes with a fully transferable lifetime guarantee from Leupold – that will cover any kind of damage at any point in this product’s life.

What We Liked

  • Reasonably priced.
  • Commendable build quality.
  • Reliable optical clarity.
  • No nonsense, traditional duplex reticle.
  • Eyebox allows for easy target acquisition.
  • Full lifetime warranty.

What We Didn't

  • Limited internal adjustment range.

UTG 3-12X44 30mm Compact Scope, AO, 36-color Mil-dot, Rings

  • Zoom Range: 3-12x
  • Objective Diameter: 44mm
  • Tube Diameter: 30mm
  • Parallax setting: 10 yards to infinity
  • Quoted Minimum Eye Relief: 3 in

If your budget is tight and you need a workable mid-to-long range optic for your AR-15, here’s a scope that manages to pack in a lot of useful features, in addition to a 12x upper zoom limit, at a very nominal price.

Featuring Leapers’ True Strength Platform in a 30mm tube design, this scope is surprisingly durable for its low cost; it is fully sealed and nitrogen filled to make it waterproof and fogproof – however, there have been a few complaints about dust / smudging on the inside of the lenses which indicate poor quality control.

The UTG 3-12x44’s magnification range and enhanced objective diameter is sufficient for longer range shootouts with your AR-15. The lenses have a multi-emerald coating to ensure optimum light transmission so you get a vivid image of the target in all light conditions. The eye clearance however, varies from 3.4” to 3”, and is a bit conservative compared to other rifle scopes.

The scope features a second focal plane mil-dot wire reticle that will help you estimate range, albeit at a fixed magnification setting. Plus, it is illuminated so you can use it at sundown. The EZ-Tap® Illumination Enhancing System is a proprietary feature that lets you specify 36 unique shades for the illumination, which can be of great assistance if you are color-blind and the usual red/green don’t work for you.

The illumination system has a specialized circuit and housing to ensure continued operation even under heavy recoil. The fact that it retains your brightness and color settings even after it has been switched off is a thoughtful touch.

The scope has finger movable knobs for elevation and winding adjustment in ¼ MOA positive clicks. While the feedback is quite tactile, the range of these adjustments is quite constrained as per feedback from consumers. However, the scope has an infinitely adjustable parallax setting thanks to a dedicated side focus adjustment turret – something that is lacking even in many of its pricier competitors.

The scope is able to hold zero quite nicely, but there have been some complaints about the adjustment system being broken so that changing the zero would have no effect on where the shots landed. The UTG 3-12x44 comes as a complete package: it packs complementary medium profile mounting rings that go on Weaver/Picatinny rails, as well as flip-open lens caps.

It goes without saying that in a budget product such as this one, poor quality control can be an issue. Furthermore, this scope is a bit heavy at 23.2 ounces and does not have a compact profile. It does come with a lifetime warranty, as is the market norm, so you can get it replaced if you find any flaws in the construction.

What We Liked

  • Very cheap.
  • Magnification setting suitable for hunting at extended range.
  • Solid True Strength main tube construction.
  • Highly effective and useful illumination system.
  • Easily adjustable, tactile turrets.
  • Limited lifetime warranty.

What We Didn't

  • Tight adjustment range, and some complaints of broken adjustment.
  • Some quality control issues – smudges / dust marks on lenses’ interior.
  • Restricted eye clearance.
  • Not compact.

NIKON M-223 BDC 600 8489 3-12x42SF Riflescope

  • Zoom Range: 3-12x
  • Objective Diameter: 42mm
  • Tube Diameter: 1”
  • Parallax setting: 50 yards to infinity
  • Quoted Minimum Eye Relief: 4 in

Created in response to the large surge in AR style rifles in recent years, the M-223, with its single piece main tube, infinitely adjustable parallax and fully multi-coated lenses that provide up to 92% light transmission, is a highly functional ranged optic befitting a professional marksman’s arsenal.

The 12x upper zoom limit combined with the 42mm objective lens diameter suffices for extended ranges. Thanks to the 4” eye clearance, you can safely fire high-powered calibers without worrying about recoil.

The scope utilizes the signature Nikon BDC 600 reticle that has markings from 100 yards to 600 yards for estimating target distance and hold-over. You can use the BDC reticle in conjunction with the Spot On Ballistic Match Program to get exact subtension values for your shooting setup.

You’re able to adjust the scope internally for up to 60 MOA, not an especially pleasing value as far AR-15 scopes go – but the adjustment knobs are tactile and allow for easy zero-reset in the field. Besides, the M-223’s mount has an inbuilt 20 MOA elevation adjustment so you can always use that if you’re planning to shoot at extra-long range. The side focus knob lets you eliminate parallax error from 50 yards to infinity – very helpful at longer ranges.

This scope has a single-piece aircraft-grade aluminum construction which ensures structural integrity while keeping the overall weight low. It is also O-ring sealed and nitrogen filled, so fogging, moisture and dust won’t be a problem. A disappointing aspect is that it is still a second focal plane scope despite being considerably more expensive than its P-223 cousin. In other words, you’re still stuck to using the BDC 600 reticle for range estimation at one default magnification setting.

While there haven’t been any major complaints pertaining to this product’s design or performance, rest assured that it packs Nikon’s solid lifetime warranty against defects, so you’re covered in the event of a shortcoming or flaw. All in all, this scope provides some of the best bang for your buck as far as AR-15 optics go.

What We Liked

  • Balanced and justified price-point.
  • Efficient light transmission.
  • Strong yet lightweight one-piece design.
  • Infinitely adjustable parallax.
  • BDC reticle lets you easily estimate range and compensate for bullet drop.
  • Plenty of eye relief.
  • Lifetime warranty.

What We Didn't

  • Not a budget product.
  • Still a second focal plane scope in spite of its higher price.


Having finished this guide – I hope you’ll understand that the most crucial factor in determining the best AR15 scope for yourself is your intended shooting distance: low-to-mid range scopes will have markedly different characteristics (zoom limits, tube size, lens diameter, internal adjustment) as compared to mid-to-high range scopes.

Still, going by the typical definition of a rifle scope i.e. an optic utility that magnifies your target and lets you aim at it from a distance, my favorite AR-15 scope is the NIKON M-223 BDC 600 3-12x42SF: sporting a solidly built single-piece aluminum construction, it has got plenty of zoom, paints a clear image of the target, lets you correct parallax, is easily adjustable in the field, and its BDC reticle allows for easy hold-over and distance estimation in conjunction with the Spot On program.

While it may not be the cheapest option out there, it packs a lot of value into its moderate price-tag, and the feedback pertaining to its performance is very positive. Combine all this with a lifetime warranty from Nikon, and you’ve got an unbeatable ranged optic package for the AR-15 platform.

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