Guide to Long Range Scopes for AR-15: Top 4 Picks, Factors

I see more and more interest in long-range or precision shooting. Many shooters want to take their AR-15 out as far as possible on the range and in the field. The challenge, beyond your won ability, is to match your rifle with the scope. A well-matched rifle and scope combination will enhance your rifle’s accuracy and allow you to go to distances you might not have thought possible.

This article will look at what I consider the top long-range rifle scopes for an AR-15 platform. Of course, there are no guarantees that any one rifle scope will perform for you. You must judge your abilities, needs, and expectations to pick the best scope for your situation. 

Judging your abilities, your needs, and your expectations, assume that you understand your AR-15. We have many new shooters who read these articles. Many of these novice shooters may not have a clear understanding of the capabilities of an AR-15. Before we look at scopes, I want to discuss the AR-15 Platform just a bit.

How Far Will It Go: AR-15 Effective Ranges

We base the effective range of an AR-15  on published military standards. The military defines effective range as the range in which a weapon is effective. To be more precise, the effective range is the distance at which a bullet will reach a target and deliver enough energy to do its job. 

An AR-15’s effective range is a topic of discussion that never loses its energy. There are as many opinions as there are shooters and rifles. To find common ground, I fall back to the factory instruction manuals that come with most AR-15 rifles. These instruction manuals typically list an effective range of approximately 550 meters (600 yards).

The Factors that Affect an AR-15’s Range and Accuracy

This approximation is based on a mil-spec AR-15 with a standard 20-inch barrel and chambered for the NATO 5.56 x 45 55 grain cartridge. Shorter barrels will usually not give as much effective distance, and longer barrels may increase the effective range. 

Different bullet weights, powder load, and powder characteristics can change the effective range of an AR-15. Lastly, the skill of the shooter is a big determinant of accuracy at long ranges.

Why Is This Important to Me?

The primary reason you need to understand a bit about ballistics and how it affects effective range is to choose the proper scope. If you intend to shoot a rifle with a maximum effective range of 1000 yards, why go to the expense of mounting a scope that will go out to 1500 or even 2000 yards.

The fact is that extra distance won’t do you any good and will cost you a lot more money. I call this scope fit. Scope fit in my book has nothing to do with the mounting of the scope. I think of scope fit as how well the scope matches the rifle’s characteristics and the shooter to provide the best performance.

A good scope fit will produce the best results for you at the best price and provide you all the features you need to be an effective long-range shooter.


What Should I Look for in a Long-Range Scope for my AR-15?

There are some features that you must have in a long-range rifle scope. Some features are good to have and some are nice but not essential. Understanding what you must have to find a good scope fit is part of the selection process. These are the things I look for in a scope.

Magnification:

If you take your rifle out beyond 500 yards, most of us can’t see the target, much less a bullseye. Without magnification at long range, your accuracy will suffer, and the effective range of the AR-15 drops. However, don’t overdo the magnification. Any magnification over 15X is probably overkill. 

Reticle:

There are about as many reticle styles as there are scopes on the market. Every manufacturer has its take on reticles. The big choices are

  • Mil-dot or MOA
  • Compensating or non-compensating
  • Illuminated or Not
  • First or Second Focal Plane

The choices are about personal preference. By and large, each of these reticle styles or a combination will perform effectively. I prefer a first focal plane MOA reticle. Illumination is a nice feature but not a necessity. A compensating reticle is handy, but you should do the same thing with any good reticle with practice.

Objective Lens Opening :

Long-range shooting is, in many ways, about light. The further out you go, the more light your scope needs to gather to create sharp, clear images, especially when magnified. The larger the objective lens, the more light the scope can gather. 


Best Long Range AR-15 Scope: Top 4 Picks

With the preceding bits of information in our hands and brains, let’s get to the business at hand. This list represents my picks of the best scope options for long-range shooting with an AR-15 platform. These scopes may not provide the best scope fit for you. The scopes I have chosen to provide the best overall options in their categories for the average shooter.

Best Overall Long-Range Scope for Your AR-15 – Vortex Optics Crossfire II 4-16×50 AO Review

Vortex Optics Crossfire II 4-16x50 AO, 30mm, Second Focal Plane Riflescope...

I admit that I am a Vortex Optic fan. If you are like me and your budget is a prime consideration in any purchase, Vortex Optics provides the best performance and features to price ratio I have found. I have yet to be disappointed with a Vortex Optics scope.

The Vortex Optics Crossfire II 4-16×50 AO rifle scope checks off almost every desirable feature on my list. This impressive range of features comes with a surprisingly budget-friendly price. Couple these with the reputation and customer service of Vortex Optics and you have an almost unbeatable combination. The features alone are enough to convince anyone that this is a great scope choice for a long-range AR-15 platform.

Features

  • Fully multi-coated lenses reduce glare and increase light transmission
  • Fast-focus eyepiece allows rapid adjustments 
  • Long eye relief gives you more options for placement on your rifle
  • Resettable MOA turrets
  • Capped recessed turrets
  • Single piece aircraft-grade aluminum tube
  • 30mm Tube
  • Nitrogen purged and O-ring sealed
  • Fogproof
  • Waterproof
  • Shockproof
  • Second focal plane reticle
  • Adjustable Objective lens
  • Dead-hold MOA compensation reticle

Specifications

  • Magnification – 4-15X
  • Objective lens diameter – 50mm
  • Field of View – 25 – 3.7 feet at 100 yards
  • Adjustment per click – .25 MOA
  • Maximum elevation and windage adjustments – 50 MOA
  • Length overall – 14.37 inched
  • Weight – 23.6 ounces

Vortex Optics Crossfire II 4-16x50 AO, 30mm, Second Focal Plane Riflescope...
  • The 4-16x50 Adjustable Objective Crossfire II riflescope is one of many configurations in the...
  • The adjustable objective provides image focus and parallax removal to the shooter while...

Last update on 2021-05-10 at 12:42 / Affiliate links / Images from Amazon Product Advertising API

These are some impressive features and specifications for a scope in this price range. Add the Vortex Optics No Questions Asked lifetime warranty and it is an almost unbeatable package. The second focal plane reticle is the only check box that this rifle scope fails to meet. However, the clarity and precision of this scope negate the lack of a first focal plane reticle.

Runner up Best Overall Long-Range Rifle Scope for your AR-15 – Primary Arms SLx 4-14X44mm FFP Rifle Scope – Illuminated Review

Primary Arms SLX 4-14x44mm FFP Rifle Scope - ACSS-Orion

The Primary Arms SLx 4-14x44mm FFP rifle scope is hard on the heels of the Vortex Crossfire II on my list as the best overall long-range rifle scope for your AR-15. Primary Arms has built a good following and created an impressive reputation in a short period. These Primary Arms scopes are underappreciated in my opinion. 

As far as features go, you won’t find many missing on the list that comes with the Primary Arms SLx rifle scope. Primary Arms has incorporated all the important items on my features list and added a few enhancements. AN illuminated reticle is among these extras.

Features

  • First focal plane reticle
  • Illuminated reticle with six intensity settings
  • High strength aircraft aluminum tube
  • Side adjustable parallax
  • Fast focus eyepiece for quick and accurate adjustments
  • 30 mm tube
  • Clear and price tactile and audible turret adjustments
  • Each click makes a 1/10 MIL change
  • Exposed tactical style turrets
  • Zero reset turrets
  • Shockproof
  • Waterproof
  • Fogproof

Specifications

  • Reticle Type – Mil-Dot
  • Objective Lens – 44mm
  • Magnification – 4-14X
  • Battery type – CR 2032
  • Field of View – 27.2 – 7.85 feet at 100 yards
  • Overall length – 12.9 inches
  • Weight – 25.2 ounces
  • Total elevation and windage adjustments – 17.4 mils
  • Adjustment per click – .1 Mil

Primary Arms SLX 4-14x44mm FFP Rifle Scope - ACSS-Orion
  • Variable 4-14x magnification first focal plane scope features the ACSS Orion reticle for...
  • ACSS Orion reticle features quick ranging and wind holds for hunting deer and coyote sized targets

Last update on 2021-05-10 at 12:42 / Affiliate links / Images from Amazon Product Advertising API

Primary Arms offers a great alternative for any shooter and a highly competitive price point. The features are comparable, and the first focal plane reticle is a plus as well. Many shooters will enjoy an illuminated reticle, especially in low-light conditions. All in all, the Primary Arms SLx 4-14×44 FFP rifle scope is an attractive and budget-friendly option.

The Ultimate AR-15 Long-Range Rifle Scope – Leupold VX-5HD 3-15x44X [email protected] Side Focus Rifle Scope Review

Leupold VX-5HD 3-15x44mm Side Focus Riflescope

If your budget can take the hit, you won’t do better for your AR-15 than the Leupold VX-5HD 3-15x44X rifle scope. There is no question that Leupold is the standard against which most other riflescopes are measured. There is no parallel in the quality of the optics or the construction of these scopes.

It is often said that the best optics often cost more than the gun on which they are mounted. This adage could very well be true if you opt for a Leupold scope. However, if you want the best in optical clarity with crisp edge-to-edge images, the Leupold is your choice. As you would expect, Leupold hits every check box on my wanted features list.

Features

  • 5:1 zoom ratio provides versatility and balance in power and magnification
  • Leupold professional-grade optics systems offer an industry best light transmission
  • Side focus system allows you to adjust the scope’s parallax for clearer reticle images and less perceived movement
  • Custom Dial System allows you to customize your turret for your settings and needs. 
  • CDS-ZL2 Zero-lock turret adjustment system prevents accidental dial movements.
  • The second focal plane reticle keeps the reticle the same size no matter what magnification you select
  • Zero-stop system prevents accidental overrun when readjusting turret settings
  • Guard-Ion lens protection system sheds dirt and water for clear and almost maintenance-free lenses
  • Waterproof
  • Fogproof
  • Shockproof

Specifications

  • Reticle Style – Impact 29 MOA
  • Weight 19.7 ounces
  • Length overall –  13.5 inches
  • Adjustment per click – .25 MOA
  • Maximum windage and elevation adjustments – 75 MOA
  • Magnification 3 – 15X
  • Field of View – 38.3 – 7.7 feet at 100 yards
  • Eye relief – 3.7 inches

Yes, the Leupold is expensive. However, you probably won’t ever need to purchase another scope. Many shooters are aiming through Leupold scopes that their fathers purchased. Some shooters consider a Leupold scope an investment rather than a purchase. If you want the absolute best scope you can put on your AR-15, consider the Leupold VX-5HD 3-15x44X Rifle Scope.

Leupold VX-5HD 3-15x44mm Side Focus Riflescope
  • Model #171717 - VX-5HD 3-15x44mm Side Focus Riflescope with Boone & Crockett CDS reticle and Matte...
  • Side Focus Parallax Adjustment - adjusts the scope's parallax for less perceived movement when...

Last update on 2021-05-10 at 12:42 / Affiliate links / Images from Amazon Product Advertising API

Best Budget Long-Range Scope for your AR-15 – UTG 3-12x44X 30mm Compact Scope Review

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

Budget is usually a consideration for all of us. Unfortunately, this often means sacrificing quality or features in the interest of staying on budget with our shooting sports purchases. The compromise of features versus cost is a set of tradeoffs that often leaves us lacking in some areas. 

The UTG 3 3-12x44X rifle scope is my choice of a budget-minded rifle scope for your AR-15 that will let you move out to the edges of the effective range of your rifle. The UTG 3 scope is a feature-rich compact scope that can deliver excellent results for most shooters. For half the cost of other comparable scopes, the UTG 3 compact rifle scope could be the solution to your long-range scope needs.

Features

  • 30 mm aircraft-grade aluminum tube construction
  • True-Strength Platform featuring sealed and nitrogen filled tube
  • Shockproof
  • Waterproof
  • Fogproof
  • EZ-Tap illumination control system (patented)
  • Red or Green reticle illumination
  • 36 color and intensity combinations of reticle illumination
  • Low profile control configuration keeps the scope sleek
  • Compatible with all large caliber rifles
  • Side adjustment for parallax settings
  • Integrated sunshade

Specifications

  • Length overall – 356mm (14.01 inches)
  • Weight – 22.7 ounces
  • Battery Style – CR 2032
  • Magnification – 3 – 12 X
  • Objective Lens – 44 mm
  • Field of View – 34 – 3.3 feet at 100 yards
  • Adjustment per click – .25 inches at 100 yards
UTG 3-12X44 30mm Compact Scope, AO, 36-color Mil-dot, Rings , Black
  • 30-millimeter SWAT 3-12X44 IE tactical range estimating scope with mil-dot, full 36-color EZ Tap...
  • 30-Millimeter tube built on True Strength Platform: sealed and nitrogen filled, shockproof,...

Last update on 2021-05-10 at 12:42 / Affiliate links / Images from Amazon Product Advertising API

UTG gets overlooked by many shooters. However, in recent years the company has refocused on quality control. In many ways, UTG has risen to the challenge and now produces some good optical equipment. For the casual shooter or entry-level optics, UTG provides a wide range of products to fill the bill for many shooters.


Before you Buy, Find the Right Scope Fit

Before you spend your money, make sure that the scope you purchase fits your shooting style and your expectations. Knowing a bit about your gun, your shooting style, and your skill level should guide your scope selection. 

I hope that this article has given you a place to start your search for a long-range scope for your AR-15 platform. My picks may not be right for you, but they illustrate what to look for and how to evaluate a scope based on your needs and goals as a long-range shooter.

If you have questions, suggestions, or experiences that you think would benefit the other readers, please use the comments section below. Your advice and knowledge are helpful to everyone, and we are, after all, here to learn from one another. Good shooting and be safe.




Written by Dennis Howard

A life long hunter, fisherman, and outdoorsman, after surviving a devastating tornado in his home town, he saw the effects on people's lives as they struggled to cope. He built his first bugout bag a few weeks later and has been a dedicated prepper/survivalist since that time. After a career as a fireman, Dennis opened a retail store (FFL approved) catering to the military, law enforcement, and like-minded individuals. The store built their own AR platforms. Furthermore, Dennis was also an NRA instructor in both long gun and handgun as well as a certified range safety officer. Read his full interview here. Read more of Dennis's articles.

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