Hey, that’s a nice optic you’ve got, there. But what happens when the batteries die or something smashes the glass?
When the worst happens, backup iron sights (BUIS) are worth their weight in gold. There are lots to choose from, and it can be hard to decide which ones are right for you — or if you even need them at all.
Today, we’re going to look at some of the best AR-15 backup iron sights we’ve used.
So get ready to dust off those old-school marksmanship skills!
THE QUICK LIST
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Editor’s Pick
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Best Metal
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Best Offset
Table of Contents
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Backup Iron Sight Comparison Chart
| Primary Material | Adjustable for Elevation | Adjustable for Windage | Orientation | Price | |
| Magpul MBUS 3 | Polymer | Yes (front) | Yes (rear) | Flip-up | $75 |
| FAB Defense Flip-Up Sights | Polymer | Yes (front) | Yes (rear) | Flip-up | $83 |
| Troy Micro HK-Style Front and Rear Sights | Aluminum | Yes (front) | Yes (rear) | Flip-up | $140 |
| Magpul MBUS Pro | Steel | Yes (front) | Yes (rear) | Flip-up | $184 |
| Surefire Rapid Transition Sights | Aluminum | Yes (front and rear) | Yes (rear) | Offset | $179 |
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
Copied! Visit Merchant
Pros
- Super lightweight
- Durable
- Affordable
Cons
- Not super refined
Specs
- Material: Polymer
- Adjustable for Elevation: Front only
- Adjustable for Windage: Rear only
- Orientation: Flip-up
The Magpul MBUS 3 is an affordable and effective backup sighting system for the AR-15 platform.
Magpul’s front and rear sights are built from lightweight and durable polymer that can handle any wear and tear you throw at it without any major issues.
With the Gen 3 MBUS, Magpul reduced the overall size of the sights they lay nice and flat. Ambidextrous buttons deploy each spring-loaded sights automatically.
The front sight features toolless elevation adjustment and a rectangular front post that lets you choose hoe thick you want it to be in your sight picture. Use the wide side for speed, or the skinny side for precision.
The rear sight has a knob to adjust windage, and dual apertures. Again, use the large one for speed or low-light environments, or the small one for daytime accuracy.
As long as you’ve got a Picatinny rail system on your gun, you’ll have no problem mounting these BUIS in minutes.
Most importantly, the MBUS 3 system is super affordable! It’s inexpensive and it works — no wonder so many people use it.
What’s your take on the Magpul MBUS 3 sights? Give it a rating below.
2. FAB Defense Flip-Up Sights – Simplest
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
Copied! Visit Merchant
Pros
- Manual opening and closing
- Clean sight picture
- Decent value
Cons
- Chunky
Specs
- Material: Polymer
- Adjustable for Elevation: Front only
- Adjustable for Windage: Rear only
- Orientation: Flip-up
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 the Magpul MBUS 3, but they don’t have an internal spring. That isn’t necessarily a bad thing.
It’s rare that you need to deploy your BUIS, and I actually like FAB’s system since you’re less likely to unintentionally activate the front sight if you use a forward C-clamp grip on the handguard.
The view-through is great, and the sights are very easy to adjust. Use the front sight to change elevation, and the rear sight to change windage.
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 Sights – Best Value
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
Copied! Visit Merchant
Pros
- Low-profile
- Positive locking action
- Strong, lightweight aluminum construction
Cons
- Expensive
Specs
- Material: Aluminum
- Adjustable for Elevation: Front only
- Adjustable for Windage: Rear only
- Orientation: Flip-up
If you’re looking for something that’s sturdy and dependable, Troy Micro HK-Style BUIS 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’re 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.
This setup is an excellent alternative for anyone who’s not so keen on polymer sights and wants something actually made out of metal – as the name iron sight implies. It’s not too expensive, either.
4. Magpul MBUS Pro – Best Metal
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
Copied! Visit Merchant
Pros
- Like the MBUS 3, but metal
- Toolless adjustments
- Low-profile
Cons
- Expensive
Specs
- Material: Steel
- Adjustable for Elevation: Front only
- Adjustable for Windage: Rear only
- Orientation: Flip-up
There is no question that the Magpul MBUS family has been considered the industry standard for some time now, but the Magpul MBUS Pro is awfully nice if you have a few more bucks to spend.
Some people just aren’t comfortable with the thought of polymer sights. Yep, these are steel — not polymer or aluminum. The MBUS Pro sights are built to withstand the harshest conditions while remaining 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, flip-up iron sights, these are the ones to get.
5. Surefire Rapid Transition Sights – Best Offset
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
Copied! Visit Merchant
Pros
- Fully adjustable rear sight
- M16-style sight assemblies
- Tritium and fiber optic versions available
Cons
- Expensive
Specs
- Material: Aluminum
- Adjustable for Elevation: Front and rear
- Adjustable for Windage: Rear only
- Orientation: Offset
All these folding BUIS are slick, but what if you want something more capable? The Surefire Rapid Transition Sights don’t cut any corners.
These are offset sights, which means they mount to the top Picatinny rail but stick out to the right at a 45-degree angle. That adds potential snag points to your AR-15, but they’re never out of service and you can switch from them to your optic as fast as you can tip your hands to the left.
More importantly, this is the only system here that has a fully adjustable rear sight. If you look closely, it’s the exact same assembly that’s on the old A2-style carry handle. That means you can dial for wind and distance on the fly.
Yes, they’re expensive, and yes, they’re kind of bulky. But if you want something fast that can accurately engage targets out to several hundred yards, these are the backup iron sights for you.
How to Choose the Best Backup Iron Sights
Backup iron sights on your AR-15 are like airbags in your car; you don’t need them until things go seriously wrong. Then, they can save your life. Let’s figure out how to pick the best AR-15 backup iron sights for you.
Materials
We call them backup irons, but they typically come in polymer, aluminum, or steel construction.
Polymer is lighter and less expensive than metal. On the flip side, metal is stronger and usually machined to tighter tolerances.
Both will get the job done. If you’re only going to be using your backup sights in close-quarters, down and dirty shooting, polymer is perfect. Don’t spend more money than you need to. If you want to stretch shots out further without an optic, look for steel sights with some degree of adjustability.
Orientation
Backup iron sights are meant to work with a red dot or scope installed. There are three main styles, and it’s up to you to decide which one you prefer.
Some align with a red dot so you can use either without moving anything — including your head. This is called co-witnessing. If your red dot goes down, just shift your focus to your irons and keep plugging away.
Most backup iron sights lay flat when you don’t need them, then flip up when you do. These are good for keeping your AR-15 streamlined but you’ll have to take the extra step to deploy them if your optic fails. Oh, and don’t forget to test them to make sure your optic doesn’t block the view.
Some people prefer offset irons. These hang off your AR-15’s top Picatinny rail at a 45-degree angle so there’s no interference between them and your optic. All you have to do is slightly rotate the firearm in your shoulder pocket to use them. This is especially useful if you’re running a DMR-style setup with a higher magnification range. Use the scope for long shots, and switch to irons for anything up close.
Adjustment
If you’re concerned about landing hits on a standard silhouette target inside 50 yards, you can probably slap most backup iron sights on your AR-15 and expect them to be pretty close out of the box (but always check).
If you want to use them in place of your magnified optic, adjustment is key. Specifically, look for a rear sight that lets you dial for elevation and wind. Once you know how to use these features correctly, you’ll be surprised how effective they are.
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 this article is Scott Murdock. Scott is a Marine Corps veteran who competed and qualified as a rifle and pistol expert while in service — with iron sights, thank you very much. In addition to shooting, Scott has written for a variety of publications, testing, researching, and evaluating guns and gear. He brings that knowledge and skillset to this article, editing and fact-checking for accuracy.
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 backup iron sights and looked at some good ones on the market, you’re ready to upgrade your AR-15.
But remember, BUIS are no good if you don’t get them sighted in. Check out our guide on how to zero iron sights.
Do you have backup iron sights on your rifle? Let us know in the comments. Want something more advanced? Check out our Best AR-15 Scopes & Optics!
Latest Updates
- March 2025: Removed the Ade Advanced Optics Offset Sights. Added the Surefire Rapid Transition Sights and comparison chart. Updated supporting content.
- October 2024: Removed Magpul MBUS Gen 2. Added Magpul MBUS Gen 3 and Magpul MBUS Pro sights.
- September 2023: Removed discontinued models.
34 Leave a Reply
Apparently the Magpul gen 3s don't lay nice and flat... As your picture plainly depicts. .. they don't lay flat on mine either..
Scalarworks is best by far - just expensive
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