Back in the day, you’d know who was a crack shot through their use of iron sights.
These days, that’s not as much of a problem for the average shooter.
Unless you’re a traditionalist, you’ve probably considered mounting an optic on your gun if you haven’t already.
What happens when the batteries on your red dot die, or your holographic takes one fall too many and isn’t working as well as it should?
This is where backup iron sights (BUIS) become worth their weight in gold. Today, we’re going to look at some reliable AR-15 BUIS to use when you’re in a pickle.
Table of Contents
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THE QUICK LIST
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Editor’s Pick
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Affordable Flip-Up Option
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Lowest Profile
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Best Metal Sights
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Affordable Offset Option
How We Chose the Best AR-15 Backup Iron Sights
We’ve shot thousands of rounds and spent hundreds of hours with guns of all kinds between our hands-on reviews, shooting events, and firearms from our own personal collections.
Input from this article came from both writers and some of the full-time staff at Pew Pew Tactical. We have had hands-on experience with almost every iron sight on this list.
We selected these sights based on reliability, durability, features, and value.
Best AR-15 Backup Iron Sights (BUIS)
1. Magpul MBUS 3 – Editor’s Pick
Prices accurate at time of writing
Prices accurate at time of writing
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25% off all OAKLEY products - OAKLEY25
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The Magpul Back-Up Sight, aka MBUS, is an affordable sighting system that is designed for the AR-15 platform. It’s an affordable and effective backup to your optical sighting system.
Magpul’s front and rear sights are both built with a lightweight and durable polymer that can handle any wear and tear you throw at it without any major issues.
With their Gen 3 MBUS sights, Magpul reduced the overall size of the sights. The reduced profile means they are very small when stowed, though they can be deployed with an ambidextrous, spring-loaded push button.
The front sight has tool-less elevation adjustment and a rectangular front post. The rear sight has tool-less, adjustable windage and dual apertures.
As long as you’ve got a Picatinny rail system on your gun, you’ll have no problem mounting these BUIS in minutes.
Both sights are capable of folding down, so you don’t have to worry about them being in your way when they’re not in use.
The internal spring system built into the MBUS helps make the sights sturdy enough to withstand bumps and knocks without unintentionally folding down.
Since the MBUS are the same height as the A2 sights, you don’t have to worry about getting used to a new pair of sights. And if you want to make any adjustments, the rear sight has an easy-to-use knob for adjusting windage, while the front sight comes with a tool for making changes to the elevation.
What’s your take on the Magpul MBUS 3 sights? Give it a rating below.
2. FAB Defense Flip-Up Sights – Affordable Flip-Up Option
Prices accurate at time of writing
Prices accurate at time of writing
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25% off all OAKLEY products - OAKLEY25
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Straight from the guys that make stuff for the Israeli Defense Forces comes the FAB Defense Flip-Up Sights.
These are lightweight polymer sights like Magpul MBUS, but don’t have an internal spring system. But this isn’t necessarily a bad thing.
It is rare that you need to deploy your BUIS, and I actually like FAB’s system since you don’t unintentionally activate the front sight if you use a far-reaching c-clamp grip.
The view-through is great, and the sights are very easy to adjust, too.
Overall, these are a great alternative if you don’t want or need the spring-loaded system of the MBUS.
3. Troy Micro HK-Style Front and Rear Sights – Lowest Profile
Prices accurate at time of writing
Prices accurate at time of writing
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25% off all OAKLEY products - OAKLEY25
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If you’re looking for something that’s sturdy and dependable, Troy Micro HK-Style MBUIS are strong enough to take a lickin’ and keep on tickin’.
These low-profile iron sights are under 1.5 inches in length and only weigh a couple of ounces. You’ll forget they are even there.
We specifically like the HK-style variant of these sights, which uses a round front aperture that is similar to the front sight you would see on an MP5 or G3. This aperture style feels like it crowds the sight picture less.
Because of their low-profile design, the Micro BUIS could require a bit more adjustment when mounted on your AR. But if you’re running a raised-top rail system, then these are great to shoot with. Troy recommends mounting them to things like the Sig Sauer 556 and the FN SCAR.
The best feature of the Micro BUIS is its rugged design. This makes it an excellent alternative for anyone who’s not so keen on the polymer sights and wants something actually made out of metal – as the name iron sight implies.
4. Magpul MBUS Pro – Best Metal Sights
Prices accurate at time of writing
Prices accurate at time of writing
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There is no question that the Gen 1-3 Magpul MBUS sights have been considered the industry standard for some time now.
Despite their reputation for excellence, some people just aren’t comfortable with the thought of polymer sights.
Magpul recognized this and eventually decided to grace the shooting world with their MBUS Pro sights. These utilize the same slim design of the MBUS 3 but feature a corrosion-resistant, QPQ-finish, all-steel construction.
Yes, steel, not aluminum. The MBUS Pro sights are built to withstand the harshest conditions while still being easy to use.
Both the front and rear sight have low-profile knobs that allow for toolless adjustment for elevation and windage, respectively.
If you want a set of ultra-tough, duty-ready sights, these are the ones to get.
5. Ade Advanced Optics Offset Sights – Affordable Offset Option
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25% off all OAKLEY products - OAKLEY25
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Don’t have the coin to spend on Knights Armament sights? Then check out well-reviewed and ultra-affordable Ade Offset Sights.
We’ve been testing them out for competitions where we leave our LPVOs at max magnification and use these bad boys for quick and dirty close-up shots.
Don’t let the price fool you, though; these aren’t plastic. These are constructed from 7075 aluminum, the same material used for most AR-15 receivers.
Additionally, these only protrude 0.2 inches directly above the Picatinny, meaning you can slide these bad boys under just about any optic, no matter how low it is mounted.
It’s up to you to decide if that’s worth it, but for quick man-sized target shots up to 25 yards, I love them.
If you are interested in offset sights, we have a full article on them here – Best AR-15 Offset Sights!
But Do I Really Need Back-Up Iron Sights?
I get it; redundancy isn’t a good look. You don’t want to be that person who has every single gadget known to man mounted on their AR-15. It can become bulky, unnecessary, and cumbersome.
The thing is, good BUIS should be neither redundant nor cumbersome. And if they are, then you’re probably doing it wrong.
The AR-15 market has come a long way from its older detachable carry-handle design.
As you already know, most AR-15s are now designed to be optics-ready. Built with rail systems are almost standard these days.
Because of this, a number of manufacturers have begun making ARs without iron sights. After all, most people rush out to buy red-dot sights or scopes anyway. Whether companies do this to cut back on manufacturing costs or because the average shooter prefers mounting their own sights is irrelevant.
So, do you actually need BUIS or not? – my answer is yes. The last thing I want is for my red dot or holographic to go haywire and be left shooting blind. Since BUIS are easy to mount and take up relatively little room, it is a good Plan B for me.
Not everyone runs BUIS, though, and that is okay. An optic or other accessories may not leave room to mount BUIS. Or maybe you just have faith in that proven optic that you bought. Either way, much of it is preference.
Why Trust Pew Pew Tactical
This article builds on the work of former Pew Pew Tactical author Brandon Harville. Brandon is an avid hunter, skeet shooter, recreational shooter, and gun collector with experience in evaluating gear like BUIS.
Editing and adding to this article is Wyatt Sloan, Jr. Editor. Wyatt is an NRA-certified instructor with previous experience as a USPSA competitor. Wyatt personally owns over 200 firearms and has 10 years of home-based FFL firearm sales. He has used his extensive experience with firearms at large to test guns and gear for Pew Pew Tactical.
Editor-in-Chief Jacki Billings runs our experienced team of gun reviewers. She is a member of the Society of Professional Journalists, ACES: Society for Editing, and the Professional Outdoor Media Association. Jacki has a bachelor’s degree in Mass Communications and has worked as a media professional for close to 20 years, specializing in gun media for almost 10 years. She uses her extensive professional journalism and editing experience to set testing protocols and editorial standards.
Final Thoughts
Now that we’ve covered the importance of BUIS and looked at some good ones on the market, you’re ready to upgrade your AR-15.
Remember, BUIS are no good if you don’t get them sighted in. For the lowdown on how to zero irons, check out our guide!
Do you have BUIS on your rifle? If not, did any of these catch your eye? Let us know in the comments below. Want something more advanced? Check out our Best AR-15 Scopes & Optics.
Latest Updates
- October 2024: Removed Magpul MBUS Gen 2. Added Magpul MBUS Gen 3 and Magpul MBUS Pro sights.
- September 2023: Removed discontinued models.
32 Leave a Reply
BUIS for distance, yes. But the idea of an optic on a rifle failing and BUIS would be needed, in a home defense, situation is very much, lets say, overrated.
If you have a home defense rifle with an optic on it, you should turn the optic off (to simulate failure) and practice using it as a 'ghost ring' in a 'home defense mindset' at distances up to about 15 - 20 yards. You center a man sized target in the optic (now turned off) 'ghost ring' (e.g. the framed glass of the optic) and you will put rounds on target suitably after a little practice. Do not think you will always have time to flip up the BUIS, and in some cases using the BUIS to align a shot may even be too long. So practice also for that eye blink moment in time that you may only have to use the optic 'ghost ring' concept in case the optic fails at that moment and you are out of time.
They are pricey as all heck but when you can find them for around $200 the Ultradyne C4 dual aperture mbuis are Worth it for the unique the unique design that allows me to more accurately and with more alacrity.
some good points raised on both sides.
now i’ll try.
1. should we really call them back up IRON sights when most are plastic?
no as long as i’ve lived they were called “open sights” as opposed to “scopes” or “optics”.
2. good reasons to have them are many, good reasons not to are few. one good reason to have and use open sights is so you know how. if you are a shtf thinker, then you should practice shtf.
3. you can say cute slogans like “ounces are pounds” and that if someone needs a backup to his optic he picked the wrong optic, but it just doesn't hold water in shtf world.
many years ago in the police academy we were told a story of a shootout where an officer died because he kept gathering the empty casings (“policing his brass”) in the middle of a firefight. the point was under the extreme stress he reverted to the most practiced behavior. apparently his habit was after each emptying of his sidearm to stop and gather the empties before reloading.
it would be a shame for one of you young fellas to have to learn to use open sights just at the moment you need to have already learned.
If the weapon absolutely needs to be sighted, and you can't trust your optic to do the job, you picked the wrong optic. One with an engraved reticle might be your better choice, powered or not, you can see it. If the optic can't suffer abuse then that weapon needs straight up iron sights only.
It's all I have on the AR pistol, which is a 125 - 150yard weapon for the most part, and a red dot would be pretty redundunt for a trunk gun. We sometimes jump on a bandwagon with all the marketing hype where guns are concerned, the reality is maybe an optic really has limited enhancement and it's loss creates a bigger problem.
Reports from the field in Afghanistan etc revealed a lot of soldiers left the BUIS in their duffel bag - ounces are pounds, and pounds are pain. Given that a red dot does have a field of view, how many try shooting it turned off to familiarize themselves having to use it that way?
I'll put the extra 2 ounces on my rifle to know that if the red dot fails, I can still hit my target with my rifle in a fire fight. Combat isn't like the COD MW2 mission where the EMP from the nuke takes out your red dot, you have no backups, and you can still shoot the bad guys accurately at 20+ yards.
which one is reliable iron sight or red dot sight ?
I’ve got the Troy full-size HK style BUIS on my Daniel. They are outstanding quality and I’m happy as hell with them.
I like the looks of the above fab sights for my new Ruger MPR. What is the brand and model of the open "blue tinted view through" in which the view photo was taken. It looks like a real nice match.
Thanks, Jeff.
I’m pretty happy with my Griffin Armament M2 sights. The same sights can be purchased with 12 o’clock base, 45 offset base, or both bases. I have them set up as 45 offset because I don’t have a quick release mount for my optic.
It's all junk. Learn to shoot irons and free you gun up. At least then you will be able to see if there's a gun under all that crap.
No junk on my AR. Some of those outfits you can't be sure there is a rifle under all the bull*hit.
Sometimes I look at all the junk stuck on the AR's and ask myself 'Is there a rifle under there?'
Dude. You realize the ADE offset sights are designed for airsoft right??? They’re for TOY RIFLES! Not a weapon you depend on to save your life.
Magpul BUIS links to a knock off copy. Be warned.
Wow, you really don't give Patriot Ordnance Factory ANY respect. Frank DeSomma worked with Diamondback to produce a "low rise" version of their standard height model, called the Micro-D.
The Diamondback rear sights have three positions, ghost ring (for CQB/CQC), large aperture (for mid-distance), and small aperture (for long distance).
Diamondback ALSO has a multi-post front sight option, where the rotating selector has several different size posts, select the post that matches the height of the target profile, and the top of that post corrects for the drop at that distance. Ingenious design and function.
Who is selecting the items for your reviews??? You are IGNORING some of the most innovative and functional stuff on the market! WAKE UP!!!!
Diamond back is hot garbage
Midwest Industries Combat Rifle Sights are probably some of the best back up sights I've used. Low profile, minimalist, and rock solid.
Hi folks! I enjoy all of the reviews on this website. Some of the best and balanced reviews that I have seen especially on firearms, etc.
On the subject of back up iron sights:
Tacticon Armament Flip Up Iron Sights
I have two of these. I would be interested to hear if you have reviewed this brand.
Sorry, I don't think we have.
Hi, Thanks for valuable staff.
Have you tried ERATAC ?
What brand is the rear flip up in the very last photo of the article?
Sig Sauer iron sights
I prefer the LWRC skirmish sights. I like that you can turn the back sight around , as opposed to flipping it up and down. The allows you to choose either short or long distance from the rear sight aperture when the rear aperture is folded flat. I'm not sure if they have a patent on this or not. It seems like such an easy thing to do, I don't know why other manufacturers haven't copied this.
My ar came without sights, I put a red dot on it, but am ready to toss it and put iron sights on. What do you recommend for a front sight. I do not have a very long rail so it would need to be barrel mount.
Magpul makes an outstanding set of 45 degree offset BUIS. They’re fully adjustable by hand, solid steel construction, fold down for an extremely low profile, and less than $200. I absolutely love them.
I learned on iron sights from my dad and for most situations and environments prefer them.
MBUS Pro. Spike's. I also have offset sights like the AAO pictured above on two of my magnified rifles. They're a very nice set for around $55 called XTS from Sportsman's Guide. Just like Deuck but 1/4 the price. I tried some that looked same from Amazon for $20 but they were crap. I'm guessing that's where AAO is sold?
I like an MBUS Pro front and KAC 600m rear. Neither were mentioned here. The KAC rear has elevation adjustment as well as wind age and it's easily adjusted. Sight in at 50 and your on out to 600.
How's the KAC Micro for distances less than 200m?
On my M&P 15 Sport 2, my improved irons Blitzkrieg Components LLC Luminescent green chevron front sight post. I only needed Walmart-sold Blue Loc-tite to keep them in place, also. That is the extent of my back up irons, too. The sights line up now very rapidly, also..
Have you had a chance to check a set of scalar works BUIS?
^Andrew Baca +1 OPS are the boss of iron sights