The 5 Best Back-Up Iron Sights (BUIS) 2021 – Review and Buying Guide

In the course of hunting or competing, the last thing you’d want would be to be without a backup Iron Sight just in case the primary optic fails. I know, I know, there are very few records of the primary optics failing.

Besides why go for these when we have much-advanced sights? Well, I will be honest here; a situation where a requirement for a backup iron sight is created is rare, given we’re talking about non-combat purposes.

Best Back-Up Iron Sights (BUIS) 2021

Then, why do you need the best back-up iron sight or BUIS? Do we even need them honestly? The answer is yes, most of the professionals know that they ultimately should and would carry back up iron sights.

Why we’ll answer in later sections- so do keep reading. So, how do we choose the right one? Which of the BUIS available out there are worth putting your money in? Well, you’ll find the answers to all these questions here, in this article.


Best Buis For The Money


Note: These recommendations are based on our personal experience, research, customer reviews, and points of view. You should consider your requirements and preferences before making a decision.


5 Top Best Back-Up Iron Sights Reviews 2021


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1. MaTech Mil-Spec Back-up Iron Sight

MaTech Mil-Spec Back-up Iron Sight

MaTech Mil-Spec Back-Up Iron Sight is one of the popular BUIS out there right now. The product has managed to gain trust for its quality, durability, and construction among other factors.

You can use the MaTech Mil-Spec Back-Up Iron Sight, just like many other iron sights, as a stand-alone sight or as a co-witness with an optic sight. Particularly, if you are looking for a backup sight for an AR rifle, this will be a good choice.

Made from solid metal and with a solid construction, this Matech product can take some serious abuse. Well, it might not be the easiest sight to install, but the thing is, it holds zero even after long use.

The slight extra weight comes from its strong construction, so it shouldn’t really be much of a bother. Simply put, for close-range shooting, this can even serve as a reliable standalone sight on your rifle.


As for long-range shooting, this can pair pretty well with any optics, given it is pretty narrow and has got the right cant.

Key features of MaTech Mil-Spec Back-Up Iron Sight
Following are the key features and highlights of MaTech Mil-Spec Back-Up Iron Sight:

  • Durable and sturdy: MaTech Mil-Spec Back-Up Iron Sight comes with a sturdy and durable metallic construction. The make and material are suited to take in a great deal of rough use and obstructions. So, even if your primary optics fail someday, you know your back up will be there, unfailing.
  • Folding mechanism: If we read our FAQ section in this article, you’ll know that foldable and flip-up iron sights are more convenient to use. MaTech Mil-Spec Back-Up Iron Sight comes with a clean and nice folding mechanism.
  • Budget-friendly: For those of you who’d like a decent product but are limited in budget, MaTech Mil-Spec Back-Up Iron Sight is a totally viable option.
  • Can be used with any optics: Given that MaTech Mil-Spec BUIS comes with a foldable function among other features it can be easily and conveniently used in a co-witnessing set up with optics to attain your desired result.
  • Recommended for Picatinny rails

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2. OZARK ARMAMENT Flip Up Backup Battle Sights

OZARK ARMAMENT Flip Up Backup Battle Sights

Simply looking at the ratings and reviews of this product can explain the popularity and quality of Ozark Armament Flip Up Backup Battle Sights.

Thousands of customers happily express their content with this backup sight Ozark Armament Flip Up BUIS comes with a spring-loaded flip-up function which means you can tuck it away while not in use.

It can co-witness with optics perfectly. Made of quality aluminium and with a construction that can stand the test of time, you can rely on this as a good back up.

All in all, it is fair to say that every penny you pay is worth it when putting to Ozark Armament Flip Up Backup Battle Sights.

Key features of Ozark Armament Flip Up Backup Battle Sights
Following are the key features and highlights of OZARK ARMAMENT Flip Up Backup Battle Sights:

  • Convenient flip-up function: Flip-up function understandably makes carrying a backup sight installed on your rifle much convenient and easier. It comes spring-loaded, making it equipped and suitable for quick deployment. Simply tuck it away when you don’t need to use it.
  • Sturdy make with high-quality aluminium: Ozark Armament Flip Up Backup Battle Sights is made of high-grade, durable aluminium and is designed to stand the test of time.
  • Can work with optics: Needless to say, it can co-witness perfectly.
  • Adjustable: Yet another feature adding to the convenience of using Ozark Armament Flip Up Backup Battle Sights is that it is fully adjustable for elevation and windy conditions.
  • Recommended for Picatinny rails

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3. Magpul MBUS PRO Steel Sight Set MAG275 & MAG276 Black

Magpul MBUS PRO Steel Sight Set MAG275 & MAG276 Black

This is yet another popular and widely purchased product. So if you want to go for the tried and tested ones, you can go for Magpul MBUS PRO Steel Sight Set.

The brand itself is known and relied on for the quality of the products it offers. Made out of high-grade steel, this backup sight boasts strength and durability. The product is most suitable for Picatinny as well as STANAG rails.

The front sight can be mounted on the Gas block. Magpul MBUS PRO Steel Sight Set is narrow enough to co-witness with optics and holds on very firmly to its position.

Key features of Magpul MBUS PRO Steel Sight Set
Following are the key features and highlights of the Magpul MBUS PRO Steel Sight Set:

  • Durable: Made of steel, this backup sight boasts strength and durability. It has an impressive construction and is designed to stand the test of time. Apparently, there is hardly any brand that can beat the sturdiness of the products from Magpul. Magpul MBUS Pro steel sight is no exception to this observation.
  • Suitable to mount gas block: Made of steel, the front sight is suitable to be mounted on the Gas block.
  • Easy to install and use: Installing Magpul MBUS PRO Steel Sight Set, unlike other good quality backup sights, is quite an easy task. Similarly, making shot adjustments is possible with this sight too.
  • Can co-witness: Magpul MBUS PRO Steel Sight Set is narrow enough to co-witness with optics. Moreover, once installed, the product holds on very firmly to its position. There is going to be no awkward angles or cants. So you don’t have to worry about adjusting it over and over again, or lacking precision.

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4. Magpul MBUS Front & Rear Flip Up Backup Sight GEN 2-247-248

Magpul MBUS Front & Rear Flip Up Backup Sight GEN 2-247-248

We’ve got a few more Magpul products down here. Given the product quality boasted by the brand, it would come as no surprise.

Now, unlike most other products mentioned here, and unlike what we generally recommend, Magpul MBUS Front & Rear Flip Up Backup Sight is made of polymer, and not of any metal.

Well, it does beat the normal polymer made backup sights out there. So, what caught our eye in this particular product is the beating it can take up, its durability, despite being made of polymer. The impact-resistant construction is pretty impressive.

Besides, if all you have been looking for is a sight that hardly adds on any weight to your gun, Magpul MBUS Front & Rear Flip Up Backup Sight is your ideal thing.

What’s more, it comes with a smooth spring-loaded flip-up function that makes it much convenient to use and store. It can securely clamp to any MIL-STD-1913 Picatinny/STANAG 4694 railed handguard.

Key features of Magpul MBUS Front & Rear Flip Up Backup Sight
Following are the key features and highlights of Magpul MBUS Front & Rear Flip Up Backup Sight Gen 2:

  • Sturdy impact-resistant construction: The impact-resistant construction of Magpul MBUS Front & Rear Flip Up Backup Sight is pretty impressive for a sight made of polymer. It can take a fair amount of beating
  • Flip-up function: The smooth spring-loaded flip-up function enables you to flip it up in an instant when needed and otherwise tuck it away smoothly as well.
  • Lightweight: The product would hardly add any weight to the product.
  • Easy installation and adjustment: installing Magpul MBUS Front & Rear Flip Up Backup Sight is a pretty simple task. Also, you can make easy windage adjustments.

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5. Magpul MBUS Sight Set GEN 2 Front & Rear

Magpul MBUS Sight Set GEN 2 Front & Rear

As it happens, we have yet another Magpul MBUS product on our list here. Magpul MBUS Sight Set GEN 2 is yet another polymer iron sight from the brand and promises quality. The product is a lot like the previous one in the list.

To begin with, this would be a great choice for those looking for a lightweight option and for those who aren’t looking to take the rifle through much rough use.

And, as we mentioned earlier, Magpul does its job pretty well when it comes to maintaining the quality of the products.

Now, while these may not be able to complete with their metallic counterparts, they seem like an attractive option for the price range in which they are available.

Installation of Magpul MBUS Sight Set GEN 2 is a simple, no-nonsense job. It is pretty much a low-profile sight and can flip in and out smoothly and nicely. All in all, it can be a fair purchase.

Key features of Magpul MBUS Sight Set GEN 2
Following are the key features and highlights of Magpul MBUS Sight Set GEN 2:

  • Lightweight: Magpul MBUS Sight Set GEN 2 can be a great choice for those who are looking to get a decent quality yet lightweight product.
  • Budget-friendly: Its price range is, of course, one of the most attractive factors for Magpul MBUS Sight Set GEN 2. Available much within the $100 line, this would be a good option for those tight in budget.
  • Easy to install: Installation of Magpul MBUS Sight Set GEN 2 is a simple, no-nonsense job. There’s no sweat involved. What’s more, it does a good job holding on to its position.
  • Flip-up: As in any other back up sight, we like the presence of the spring-loaded flip-up feature.
  • Suitable for Same Plane guns

Frequently Asked Questions on Back-up Iron Sights (FAQS)

In this section, we discuss the questions that we often receive from the readers in relation to iron sights, purchasing them and using them.

What is an Iron Sight?

Best Back-Up Iron Sights

If you are new in the world of ammunition, here’s the easiest way to understand what an iron sight is. Take it, more or less, as another name for the open, mechanical sights.

Iron sights are usually made into most of the guns made these days. But the point is, these which come readily made by the gun manufacturer are more or less a formality.

They can’t stand a fire-fight situation and may not be designed for long-range accuracy. That’s why you should have a better option as a backup.

Now, much contrary to what the name suggests, an Iron sight is rarely ever made of iron. It is usually made of Aluminium, plastic or steel.

Now, though different make and material may have some slight advantage over the alternative ones, they pretty much serve the same purpose.

They use to be standard on most rifles, typically with one front sight post and rear sight.

While iron sights were popular earlier, with the development of optics, the use of these types of sights has considerably decreased.

However, even though the advent of technology has made the use of iron sights pretty much a lost art, they are still in use- a lot.

Most commonly, iron sights are kept as backup professional hunters and shooters. They are also attached to a different optical point to obtain a faster target transition.

Usually, and as is recommended by many professionals, the back-up iron sights are kept folded until the primary optics fail and the backup sights need to be put to use.

Furthermore, many professional hunters and shooters use iron sights along with the red-dot sights in such a manner that they both co-witness the target object.

What to look for when buying a backup iron sight?

While looking for the best backup iron sight, there are some factors to be kept in mind. Given below are some of the most important factors and minor details to note while you are out for BUIS shopping.

Flip-up types: There are many sights that have a spring or a turn-down mechanism in place to flip it up or down as the situation may be. We personally recommend the ones that can flip up.

Having this option would mean you don’t have to remove the sight to store it when you don’t need it.

You can simply have it flipped down to when it isn’t in use and can flip it up in a moment when you need it.

So, simply speaking, the flip-up types are convenient and while helpful in saving time and effort.

Compatibility: Of course, this goes pretty much unsaid. What’d be the use if, at the end of the day, it doesn’t fit your rifle?

Make sure that you select a quality set of iron sights which you can say, for certain, are compatible with the rifle on which you intend to install them.

An incompatible iron sight would simply be another item in your store that would serve you no good. So, compatibility is an essential prerequisite.

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