3 Best Red Dot Optics For AR15 Under $300 [Works For Others Too]

Referenced Movie Helios

No matter what types of rifle carbine you have, you need an optic for it. In this buyer's guide, we focus on bringing you the best red dot optics for AR15 under $300, as the optics technology continues to improve & prices are dropping without quality compromises.

The most popular ones are Holosun 510C for its large objective lens and reduced "tube effect" great for CQB types of shooting, and the other is Aimpoint Micro alike optics from Sig Sauer & Holosun. 

Back in the day shooters have to spend over usually around $550 for a good optic, but today budget option red dot sights' quality are catching up and save you money.

If you want to check out the high end stuff, please check out this guide instead. Otherwise let's check out what you can get for under $300.

So let's start!


 DISCOUNT CODE AVAILABLE

Best Red Dot Sights for AR Under $300

If you believe budget reflex sights ONLY belong to airsoft, you're wrong!


Optic
Our Best Pick
Trijicon MRO
Aimpoint Micro T1
Holosun HS403R
Leupold LCO
Trijicon MRO-C-2200005 1x25mm Miniature Rifle Optic (MRO) Riflescope with 2.0 MOA Adjustable Red Dot Reticle with Full Co-Witness Mount
Aimpoint 200055 Micro, T-1 (2 MOA No Mount-Cardboard Box)
HOLOSUN HS403R Micro Reflex Sight, Black, 2 MOA Red Dot, 10DL & 2NV Brightness Settings, Rotary Switch, Multi-Layer Coating, Waterproof IP67, w/Lower 1/3 Height Mount & Low Base, CR2032, 100,000 hrs
Leupold Carbine Optic (LCO) Red Dot Sight
Construction
7075 T6 AL
7075-T6 AL
6061 T6 AL
6061-T6 AL
Weight
4 - 6 oz
5 oz
3.53 oz
9.5 oz
Objective Lens
1X25mm
1X18mm
1X20mm
1X32mm
Dot Size
2 MOA
2 , 4 MOA
2 MOA
1 MOA
Reticle
Center Dot
Center Dot
Center Dot
Center Dot
MOA adjustment
0.5 MOA / Click
0.5 MOA / Click
0.5 MOA / Click
0.5 MOA / Click
Battery
CR2032 5 years
CR2032 5 years
CR2032 100K hrs
CR123A
Motion Activation
N/A
N/A
Yes
Yes
Mount
Aftermarket
Aftermarket
Aftermarket
Factory
Our Best Pick
Optic
Trijicon MRO
Trijicon MRO-C-2200005 1x25mm Miniature Rifle Optic (MRO) Riflescope with 2.0 MOA Adjustable Red Dot Reticle with Full Co-Witness Mount
Construction
7075 T6 AL
Weight
4 - 6 oz
Objective Lens
1X25mm
Dot Size
2 MOA
Reticle
Center Dot
MOA adjustment
0.5 MOA / Click
Battery
CR2032 5 years
Motion Activation
N/A
Mount
Aftermarket
Optic
Aimpoint Micro T1
Aimpoint 200055 Micro, T-1 (2 MOA No Mount-Cardboard Box)
Construction
7075-T6 AL
Weight
5 oz
Objective Lens
1X18mm
Dot Size
2 , 4 MOA
Reticle
Center Dot
MOA adjustment
0.5 MOA / Click
Battery
CR2032 5 years
Motion Activation
N/A
Mount
Aftermarket
Optic
Holosun HS403R
HOLOSUN HS403R Micro Reflex Sight, Black, 2 MOA Red Dot, 10DL & 2NV Brightness Settings, Rotary Switch, Multi-Layer Coating, Waterproof IP67, w/Lower 1/3 Height Mount & Low Base, CR2032, 100,000 hrs
Construction
6061 T6 AL
Weight
3.53 oz
Objective Lens
1X20mm
Dot Size
2 MOA
Reticle
Center Dot
MOA adjustment
0.5 MOA / Click
Battery
CR2032 100K hrs
Motion Activation
Yes
Mount
Aftermarket
Optic
Leupold LCO
Leupold Carbine Optic (LCO) Red Dot Sight
Construction
6061-T6 AL
Weight
9.5 oz
Objective Lens
1X32mm
Dot Size
1 MOA
Reticle
Center Dot
MOA adjustment
0.5 MOA / Click
Battery
CR123A
Motion Activation
Yes
Mount
Factory

Holosun 510C - Best Overall

holosun 510c on CMMG rifle

Why people love this one - HoloSun makes some of the most popular optics for handguns, rifles and shotguns on the market right now. A company that started making budget option red dot sights, now they are making Tier 1 quality products from solar-powered optics to innovative laser/IR technologies that benefit a wide range of shooting applications.

Large Lens Window For Faster Shooting - Lens size is an important spec of how fast you shoot and track the dot in a match, parallax-free holographic sight with unlimited eye relief with this large POV to instantly place the dot on the target while shooting on the move or transitioning with both eyes open

Use the Optic As Long As You Want - Power source is an important part of a high-quality optic for non-stop use, increase battery life with the new Solar Failsafe system to strengthened reliability and longevity

Multi-Purpose For Various Firearm Platforms - Use it on any firearm is a good indication of how useful the optic is, using the improved QD mount with an adjustable clamping force to go on any firearm including heavy caliber centerfire rifles

Large Lens Window For Faster Shooting - Lens size is an important spec of how fast you shoot and track the dot in a match, parallax-free holographic sight with unlimited eye relief with this large POV to instantly place the dot on the target while shooting on the move or transitioning with both eyes open

At this price point, which is the lowest it’s ever been for a reflex sight like this one, You’ll save a ton of money. Just make sure to click the button below for the best deal.

Holosun 515GM - Aimpoint Micro Alternative

Holosun 515GM
"I have tested the Holosun 515GM long enough, and it performs extremely well, and I believe this is the bang for your buck you can possibly get" - John Lovell (Former Spec Ops), Warrior Poet Society (Watch His Review Here)

For people who love Aimpoint Micro - Holosun 515GM is an affordable option for people who love the Aimpoint Micro but don't want to spend over $800. It looks and feels just like an Aimpoint Micro at 1/3rd the price, and the battery lasts about 50,000 hrs like the Aimpoint.

As far as durability goes, the HS503GU is made with 7075 T6 aluminum body up to the mil-spec standards. The optic shares the same mounting footprint as the Aimpoint Micro so you can use the same mount.

Besides the obvious, the HS515GM features its 65 MOA ring with a center dot for faster CQB target acquisition than just a 2 MOA dot. The user can also toggle switch to a 2 MOA dot for eliminating reticle obstruction by holding the "-" button for 3 seconds. Vice versa

Added Honeycomb flash hider - For tactical advantages, the Honeycomb flash hider eliminates lens glare so bad guys can't see you during sunny daylight

Recoil proof - The optic can retain zero perfect when handling 9mm, 5.56, 7.62 and 6.5 CM recoil, so use this with confidence on your AR and other carbines.

Holosun 507C - For Low Profile & Offset

Arisaka-Defense offset optic mount

Better option than Trijicon RMR - The Holosun 507C is clearly beating the Trijicon RMR on sales because it's affordable and has the same durability.

Low profile optic setup - If you want a super low profile, lightweight and low drag setup, the Holosun 507C is the go to for a compact & streamlined carbine setup as well as a viable offset red dot option 

Cost Effective - One thing people love about the Holosun 507C is it's much cheaper than an RMR and it does the same thing, and it shares the same mounting footprint, so if you don't have to buy a special mount for the 44 mag revolver if it already has picatinny top rail.

Another feature the Holosun 507C has is the multi-reticle system, which allows the user to pick from:

  • 2 MOA Center dot
  • 32 MOA circle
  • 32 MOA circle + 2 MOA Dot

*Change by pressing the minus button for 3 seconds.

The 32 MOA circle helps significantly for picking up the sight faster because it's big and easier to see.

For the cost of this optic, you can get almost 2 Trijicon RMR’s. The battery life is great, and you will not disappoint. Check out the link below to get the best deal on OpticsPlanet

Holosun optics are definitely leading the reflex red dot market for budget option shoppers as well as high end users, please check out this guide for Holosun products for more information


Also Work For These Rifles

MK18 SBR

DD MK18 with EOTECH and PEQ2

MK18 rifles are popular for Close Quarter Battle (CQB) fans for its short barrel configuration. The faster maneuver, Lighter weight & More compact, which gives the shooter an advantage in vehicles and other tight spaces.

It's basically a short barrel version of M4A1, suited for CQB military operations. Typically associated with special forces, VIP protection details, and other high profile government agencies.

But... it doesn't mean civilians can't have it. In fact you can buy one from your local gun shop today, pair it with an optic and go have some fun on the range.

SIG MCX RATTLER

Rattler MCX with Sig ROMEO4S

The 5.5″ barrel Rattler MCX is designed for 300 AAC Blackout, with an effective range up to 100 yards, but definitely not past 150 to 200 even using supersonic 300 BLK ammo un-suppressed.

It’s definitely a CQB gun and you can use any optic, but we recommend is low profile ones that fit the PDW profile.

Something small and compact like a micro red dot used on pistol.

What To Look For RDS Under $300

Optic Accuracy & Toughness

FN SCAR 16 with Leupold LCO

Image Referenced Leupold

Any red dot optic recommended above will have absolutely no issue with accuracy on any weapon system whatsoever. As long as you mounted the optic on a high quality mount properly with a calibrated torque wrench to the exact torque spec.

This means any physical abuse, extreme temperature or sharp repeated recoil will not affect the optic's accuracy at all.

For battle ready rifles like the MCX and SCAR, you should run these optics on them with confidence.

Read More: How to shoot with red dot sight - Ultimate Guide

Strong Zero Retention

Rifle platforms like the AR15 or even the FN SCAR 16 produce a very small amount of recoil compared to a 7.62 X 51mm round. All the recommended optics above will not only hold zero, but they can hold zero even if you beat the crap out of them.

Some of these optics are rated to withstand recoil impulses way above the 5.56mm caliber cartridge, so if you're picking a sight to do full-auto fire or hardcore training classes you will have no problem with any of them.

In addition, these recommended optics listed above can tolerate extreme high & low temperatures without any reticle thermal shift, which also means it is still accurate regardless of any weather condition.

NOTE: It's NOT absolute MUST to have the most expensive red dot sight to retain zero & withstand repeated recoils, most budget sights over $150 can hold zero fairly well when paired with a good mount. Something like the Holosun series red dot sight can definitely do the job.

Long Battery Life Up To 50K Hours

Many shooters leave their red dot sight on for the entirety of the time they have it. So when you buy your first red dot sight for a tactical carbine, remember to get an optic that has as much battery life as possible so when you need it, it's ready for you.

The absolute toughest red dot sights available are made by Aimpoint. Either the Aimpoint Micro or the Comp series, all have the longest battery life over 4 years. On some Aimpoint models, the battery life is up to 10,000 hours or about 5 years.

Note: Optics like the HoloSun 403R and the Leupold LCO have a motion sensor feature that activates the red dot as soon as you pick it up. When it sits still and quietly in the safe, it turns off for battery saving.

In fact, with a motion-activated red dot sight optic, you save plenty of battery as much as a red dot sight that doesn't shut off at all.

Minimal Lens Tint

Red dot sight lens is the first thing you should look at because it can affect clarity. Generally speaking the lens tint isn't a big deal until you put one next to another optic, then you will see the difference dramatically.

In the best-case scenario, you want a optic with super clear lens so that it doesn't affect your viewing experience.

MOA & Brightness Adjustment

There are only three things you really need when checking out an optic's MOA and brightness adjustment features.

  1. Can all the settings accommodate all the lighting conditions?
  2. How tight are each adjustment clicks? usually, that's the first sign regarding the quality of the optic
  3. Easy to remove the protective cover in the field?

Out of all the optics we picked out above, all of them have a great feel in your hands and they're easy to adjust in the field without special tools. However, the Aimpoint Micro has me concerned for its proprietary MOA adjuster tool, which also serves as the protector cover.

If you lose it in the field and you can't find it, then you can't adjust the MOA clicks at all. You can't even use a shell casing or a quarter to do the job unless you take off the other one of either the elevation or windage knobs.

Mount Options

SIG MCX elevated optic height

Image Referenced TREX ARMS

Depend on if you're mounting your optic on the Sig MCX, FN SCAR 16 or the AR15, since short-stroke piston-driven rifles like the Sig MCX & SCAR 16 have higher top rail than a regular AR15, it lift up the optic height too for a good reason.

Depending on your normal cheek height on the MCX or the SCAR. I recommend getting an absolute co-witness height optic mount for the MCX & SCAR  in order to make it feel like a 1/3rd co-witness sight on the rifles. In my opinion, the Sig MCX & the SCAR have way better mount height flexibility than the standard AR15, as you have more wiggle room to account for wearing a facemask.

Trijicon MRO Geissele Optic Mount

Image Referenced Highjak86 (YouTube)

Having a durable optic body and a solid mounting system will ensure the optic stays tight on the rifle. Some optics like the Leupold LCO & Trijicon MRO come with factory default mount, and others require you to buy aftermarket optic mounts.

Aimpoint optics are known to be expensive, and they come without a mount.

Don't worry! there are many great mounts out there, one brand, in particular, is the Scalarworks mounts.  All made out of 7075-T6 aluminum, super lightweight and affordable

If you're looking for the best Aimpoint mounts please read the article below:

Read More: Best Aimpoint Red Dot Sight Mounts Under $150

MOA Size Selection - 2 MOA Is The Best

Red Dot Sight MOA Sizes

Red dot sight reticles come in many shapes and sizes, the most common is a circle dot.

The 2 MOA dot size is the standard for most carbine rifles on the market. 2.5 MOA or higher are made for close-range shooting, and 1 MOA is optimal for long-range engagement because it has a finer dot for accuracy.

Make sure the dot sizes are big enough for you to easily see but not too large to obscure targets. Tactical rifles like the SCAR16 or Sig MCX are capable of reaching out to 300 meters or more, so a 1 MOA or 2.5 MOA dot sizes are perfect for them.

Reticle

You want a simple reticle either a 2 MOA or 1 MOA center dot, or may be a center dot with a ring around for fast target acquisition.

Please avoid weird reticle patterns generally found in reflex sights made for airsoft.

Parallax Free Reticle

DD MK18 with Aimpoint Micro H1

When the optic spec tells you that their red dot sight has zero parallax, it really means it's good enough but NOT completely. A parallax free reticle eliminates the need for the shooter to keep both eyes open without fully align with the sight.

Anywhere you place the red dot is where the bullet is going, which is a great feature for close quarter combat rifles where some times the shooter need to shoot in improvised shooting positions.

Out of all the recommended red dot optics such as the Aimpoint Micro has the best parallax up to 15 yards. Anything closer for example 2-4 yards, generally speaking, you will notice some vertical parallax shift as you move your head position around.

The Holosun 403R is also a good one for the affordable price you pay for.

Read More: Best Holosun Red Dot Sights For The Money

Battle Proven Construction

7075-T6 forged aluminum is the toughest construction for a red dot sight, and the next down is the 6061-T6 aluminum for most optics under $300.

If having a tough as the Terminator is an important standard for a red dot sight on your home defense gun then we recommend the Aimpoint..

Target Acquisition Speed & Wide Field Of View

Aimpoint on Sig Sauer MCX

Image Referenced TREX ARMS

When using a low profile and low view obstruction red dot sight, the shooter can easily acquire targets faster than with a magnified scope. When using a short barrel SCAR 16 or MK18 style rifles, you expect to be in close-quarter so the speed is everything.


Final Thoughts

These red dot optics under $300 are picked for budget red dot options for AR15 type users.

Budget reflex red dots in 2020 and forward don't really mean crappy products. In fact, as optics technology improves overtime and the demand increases, the price will continue to drop.

These $300 range red dot sights have performed very well in the shooting community in the past couple years. Initially they were questionable to mount on real steel guns, but after seeing so many positive experiences people have with them, and they have set the standards for what a budget optic should be all about.

I hope you find this content helpful and please checkout other content on our site.