Home » Best Scope for AR-15 Under $100 (Top 5 Reviews – 2021)

Best Scope for AR-15 Under $100 (Top 5 Reviews – 2021)

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Maybe you are a beginner or professional looking for a backup scope and don’t want to spend thousands of dollars on an AR-15 scope. Well, you are in the right place.

Buying cheaper scopes carries a huge risk. Is it durable? Will it improve accuracy? Does it have good optics on high zoom? Questions that can only be answered after detailed testing.

Well, we did exactly that. After testing 20+ cheap scopes, we ranked 5 of the best scopes for AR-15 under $100 based on durability, optics quality, brand value, and ease of use.

Let’s dig right into it.

If you want to make a quick-fire purchase, I summarized my favorite scopes below:

  1. UTG 3-9X32 BugBuster AO ScopeTop Pick
  2. Bushnell Trophy TRS-25 Red Dot Sight RiflescopeMost Affordable
  3. Centerpoint Optics MSR Rifle Scope
  4. Bushnell Banner Dusk & Dawn Riflescope
  5. Monstrum S330P 3X Prism Scope

In case you need a little more info before buying, below is a brief comparison of the 5 picks.

Best Scopes for AR-15 under $100

Image Product
UTG 3-9X32 BugBuster AO Scope
  • Quick-detach makes dismounting quick and easy
  • Reticle gives range estimations for accuracy
  • 9x magnification makes it ideal for 400-500 yards
VIEW ON AMAZON → READ REVIEWS →
Bushnell Trophy TRS-25 Red Dot Sight Riflescope
  • You have 11 brightness settings to choose from
  • The cheapest scope on the list as it costs less than $70
  • Get range estimation for accurate shots
VIEW ON AMAZON → READ REVIEWS →
Centerpoint Optics MSR Rifle Scope
  • Military-grade build for excellent durability
  • Dual reticle colors and multiple brightness levels to choose from
  • Reticle etched on glass for better visibility in low light when battery finishes
VIEW ON AMAZON → READ REVIEWS →
Bushnell Banner Dusk & Dawn Riflescope
  • Multi-X reticle for accuracy and excellent visibility
  • Get holdover and windage estimations with MOA reticle
  • 6” eye relief and quick-focus eyepiece for quick target acquisition
VIEW ON AMAZON → READ REVIEWS →
Monstrum S330P 3X Prism Scope
  • Maintains Zero for 100+ shots making usage easy
  • Red and Green reticle colors with multiple brightness levels
  • Aircraft-grade aluminum build for excellent durability
VIEW ON AMAZON → READ REVIEWS →

But if you want to get your hands dirty and dig deep into the details, this section is for you.

1. UTG 3-9X32 BugBuster AO Scope

UTG 3-9X32 1' BugBuster Scope, AO, RGB Mil-dot, QD Rings , BlackCheck Latest Price on Amazon

Scopes under $100 can offer great value for your money by improving accuracy and being super easy to use. Well, the UTG 3-9×32 by BugBuster is primed to do just that, and here’s why.

One of the best things about this scope is that it comes with an illuminated reticle. This means whether you are hunting at dawn or dusk, the reticle remains crystal clear even if the target is 100 yards away or 25 yards or irrespective of the background.

Another myth the UTG manages to crack is that cheap scopes aren’t durable. To be true, this bad boy can take punches (handle the bumps and hits that come with hunting in the wild) just like any premium scope. 

This comes down to its metallic build which in tandem with the special SSS design gives the scope, not just great durability but also recoil-resistance by better controlling the interaction between the inner and outer scope tubes.

This build coupled with the o-rings makes the scope rainproof, so weather never plays spoilsport with your hunting trips. There’s also the nitrogen purge that prevents the scope’s glass from fogging up.

While good durability is important, one buys a scope primarily to increase accuracy, and the UTG did exactly that with its Range Estimating Mil-Dot Reticle that gives pin-point accurate windage and elevation readings with crosshairs across the reticle.

In total, you’ll find 19 aiming points or 21 if you count the inner tips, which is much higher than the 9 aiming points most other scopes give (even some high-end ones).

Adding to this are the accommodating eye relief and the wide field of view that not only provides you a clear and wider view but also ensures all that recoil does not give you a black eye.

The turrets are another plus point of the scope. Unlike most cheaper scopes, here the turrets are numbered, and considering how smooth they are and their audible clickety-clack, getting precise adjustments requires minimal effort even if you are a newbie.

Plus, they won’t budge an inch (come what may) thanks to the locking feature (bumpy roads or constant mounting/dismounting, set them once and forget it). They are also equipped with a reset system that takes mere seconds and makes zeroing in a breeze.

That’s not all.

The scope also has a 9x magnification and even at full magnification, the optics are clearer than most other scopes in the price range. This is not only because UTG uses a better lens but also the additional layers of the anti-reflective coating that disperses light better.

And to ensure the display remains good for years, attached are flip-up covers that keep out dust, dirt, oil, and scratches further saving you a few bucks as the lenses won’t need a replacement for years.

Also, included in the box are rings (another thing you won’t find in cheaper scopes) that fit onto any Picatinny or Weaver rail with ease. And when you need to dismount it, it takes a few minutes as it has a quick detach system.

Pros

  • The reticle has 2 illuminations to choose from
  • Works in rain and can take a few bumps
  • Get pretty accurate range estimations so you don’t waste ammo
  • Detach in minutes with quick detach lever locks
  • Turrets are numbered and smooth for precise, quick adjustments
  • 9x magnification is ideal for 300-400 yards
  • Excellent eye-relief and large field of view
  • Comes with rings that mount on almost any Picatinny or Weaver rail

Cons

  • No adjustable brightness
  • Not submersible in water

Check Latest Price on Amazon

2. Bushnell Trophy TRS-25 Red Dot Sight Riflescope

Bushnell Trophy TRS-25 Red Dot Sight Riflescope, 1x20mm, BlackCheck Latest Price on Amazon

If you are looking for budget red dot sights, there’s always a Bushnell around, but there’s more to their scopes than just their low cost. Here’s all you need to know about the Trophy TRS-25

One of the best features here that even the UTG lacks is the adjustable brightness of the red dot. With 11 brightness settings to choose from, you will find it easier to acquire targets when you are hunting at dawn or dusk. And adjusting the brightness takes mere seconds with the dial.

Further adding to the accuracy is the MOA reticle, which means you get accurate range estimations and can make adjustments using the smooth dials. 

The long eye-relief is another plus on the scope. It gives you the freedom to shoot with both eyes open making it one of the easiest to use. There’s also a quick focus eyepiece that ensures you latch onto any target in a matter of seconds and aren’t left twisting and turning knobs for hours.

For a scope that costs less than $70, even the durability is commendable, and I was pleasantly surprised that it was waterproof thus giving anyone the freedom to work in rain or even drop it in a puddle.

This is mainly because of the strong aluminum build and the tightly sealed o-rings that also keep out dust. You can’t drop it too hard, but a few bumps won’t scratch or break the scope.

For the price, its versatility is another feature I love. From muzzleloaders, pistols, shotguns, to even rifles, it mounts on pretty much anything and everything making it all in one red dot sight. And mounting takes less than 5 minutes making it one of the easiest to mount.

It is also one of the most compact red dot sights on the market and weighs a mere 0.2 lbs. So whether you have to move around with it when mounted on a rifle, or carry it over hilly terrain in a bag, you barely feel the weight of it. 

As for the optics, it is decent. As long as you don’t plan on shooting at distances above 200-300 yards, it should work just fine. Even if you were hunting in the rain as the nitrogen purge prevents fog build-up on the lens

One downside though of the scope is its battery life. It will give you between 2-3k hours on low settings but if you use it on full settings, you’ll either need to carry battery packs or charge it regularly between your trips for uninterrupted usage.

Pros

  • Easy to mount and detach
  • Aluminum build provides it excellent durability
  • It is waterproof 
  • Nitrogen purge keeps the lens from fogging up.
  • 11 brightness settings for hunting at dusk or dawn
  • MOA reticle gives accurate range estimations
  • Dials are smooth and grippy for precise and quick adjustments
  • Works with muzzleloaders, rifles, pistols, and even shotguns
  • Compact and light thus easy to carry and store

Cons

  • Low battery life
  • No magnification

Check Latest Price on Amazon

3. Centerpoint Optics MSR Rifle Scope

Centerpoint Optics 1-4x20 MSR Rifle Scope with Offset Picatinny Mount and Glass Reticle BlackCheck Latest Price on Amazon

Not a brand you might have heard very often, but their MSR rifle scope is definitely worth the consideration for anyone on a budget and here’s why.

Built using military-grade materials and finished with an aluminum alloy, this scope is also capable of taking a beating making it a reliable purchase ideal for long-term use, especially if you use them with AR Rifles and Airsoft guns.

The MOA reticle has been designed for accuracy with crosshairs for range estimations. Plus, it remains pretty stable and works just as well in low light thanks to the illumination. Battery life is a bummer but since the reticle is etched onto the glass, it remains pretty clear even in low light.

You can also switch between red and green reticles. The reticle is an SFP reticle and thus remains large and clear at all times, unlike FFP reticles that need to be on full magnification or can become too small.

Talking about the magnification, you can zoom to up to 4x. Much lesser than other scopes but good enough for about 250 yards. Even the optics are pretty good to this point. Furthermore improving aim is the parallax-free design and the long eye-relief as acquiring moving targets takes just seconds. 

Mounting the scope is easy and can be used with any rifle or shotgun that has a Picatinny rail. Also, included in the package are covers. While these aren’t as easy to use as flip-up covers, they still do the job well.

Pros

  • SFP reticle remains large and bright under any situation
  • Military-grade build means it will last you for years
  • Dual reticle illumination for visibility in low light
  • Get range estimations with MOA reticle
  • Parallax-free design and large eye-relief for easy target acquisition
  • The reticle is etched onto the glass for visibility in low light
  • Easy to mount and dismount
  • Compact and lightweight

Cons

  • No multi-coat on the lens
  • Poor battery life
  • Magnification is lesser than other scopes

If you need something for a distance less than 300 yards on the cheap with excellent resilience, this is the scope for you.

Check Latest Price on Amazon

4. Bushnell Banner Dusk & Dawn Riflescope

Bushnell Banner Dusk & Dawn Multi-X Reticle Riflescope with 3-Inch Eye Relief, 3-9X 40mmCheck Latest Price on Amazon

Bushnell was never going to stay off the list for too long, and their Banner Dusk and Dawn riflescope is another one of their most popular models. Here’s why I and so many other users have come to appreciate it.

One of the best things about the scope is the optics quality. Equipped with a higher-grade multi-coated lens, it gives HD quality visuals to about 7x, and even at 9x, the blurring is only minor.

Yes, it has a 9x magnification that is pretty much the most you will get at this price range.

Another thing most people appreciate is the DDB or Dusk and Dawn reticle that manages the brightness by itself to a large extent giving you decent picture quality in low light situations. 

Plus, the Multi-X reticle means it has a large, black outside with a thin center. This means clarity while maintaining accuracy.

Also, there is a long 6-inch eye relief and quick focus eyepiece that ensures acquiring targets whether still or moving is a breeze.

Furthermore, I was also impressed by its strong construction. The aluminum build makes it rock-solid while the sealed o-rings keep out water allowing you to leave it submerged even if it were for 5-10 minutes.

Coming to the turrets, they aren’t numbered but I like the audibility and smoothness as it requires little effort. They are also pretty tall, so gripping them is easy.

Furthermore, the turrets are capped. While this prevents you from making quick-fire adjustments on the go, it does ensure the turret remains in position throughout irrespective of your movement. Plus, it adds a layer of protection.

On the downsides, the reticle isn’t illuminated. While that eliminates the hassle of batteries, it does restrict its use in low light. 

Pros

  • Comes with 6-inch eye relief and quick focus eyepiece
  • Multi-X reticle has a thin center for accuracy and remains thick outside for better visibility
  • Good optics even at 9x magnification
  • Capping ensures turrets hold position and provided add protection
  • Equipped with long 6-inch eye relief and quick focus eyepiece
  • The aluminum build makes it very durable
  • Turrets have good audibility and are smooth
  • It is 100% waterproof and can remain submerged

Cons

  • No illuminated reticle 
  • Turrets are not numbered
  • Does not hold zero well

Check Latest Price on Amazon

5. Monstrum S330P 3X Prism Scope

Monstrum S330P 3X Prism Scope | BlackCheck Latest Price on Amazon

 Last but not least comes the Monstrum S330 Prism Scope, another brand well-known for its cheap yet quality scopes. Here’s the good, bad, and ugly about the S330P scope.

It has only 3x magnification, but I liked the visual quality. The lens is multi-coated, plus it uses a special prism system for better light transmission, which keeps the images sharp and bright even when you hunt in low light.

Yes, hunting at dusk or dawn is easy with the scope also because the reticle is illuminated. Along with multiple brightness levels, you also have the option of viewing the reticle either in red or green. Switching between colors and brightness is a breeze with the conveniently located dial.

The 6061 Aircraft Grade Aluminum build gives it the strength needed to handle the rigors of the wild, so few bumps and hits mean the scope won’t break or scratch.

Even with that strong build, the scope remains light and compact. It measures just 5 inches in length, so you should have no trouble fitting it in a bag and takes up little space on the rifle as well. 

And since it weighs a mere 15 ounces, it does not hamper your movement in any way. These features also make it easy to store when the scope isn’t in use as it fits in any cupboard or shelf.

It is also water-resistant. This means while you can use it in the rain, you do not want to leave it submerged in water for too long. 

I also like its turrets. A little harder than the others, but they loosen up in a while and have good audibility. They are also numbered though I would have preferred if the color of the numbers and markings were white as it would improve their visibility

Another downside of the scope is the eye relief. 3.5 is standard but I would have liked it a little more, especially since some of the other scopes have about 6” eye-relief. 

The field of view is clear though, and I love how it holds zero for 100+ shots which adds to the convenience of using the scope.

Pros

  • It is water-resistant and usable in rain
  • Aircraft-grade aluminum build provides durability
  • Clear field of view 
  • Maintains zero for 100+ shots
  • The reticle is illuminated with multiple brightness levels
  • You can choose between red and green color
  • Lightweight at 15 oz and compact

Cons

  • Bigger eye-relief would have been better
  • Ideal only for distances of 200 yards due to low magnification
  • Turrets marking and numbers should have been white

Check Latest Price on Amazon

Conclusion

Well, those are my top picks for the best AR-15 scopes under $100. Are you using any of these scopes or have used them in the past?

We are constantly looking to update our reviews based on user experience, and your insights can help many. So don’t forget to either drop a comment or use the contact form on the contact page.

You can also send in your questions about these or other AR-15 scopes that you are considering.

About Author

James Towndrow, a NRA-certified Firearms Instructor. During a career of 18 years had won several shooting competition including major leagues. Taking all those experience down the road, is now a successful Shooting Instructor in Texas, US.


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