The 4 Best Flip Up Sights for AR 15 — Reviews of AR15 BUIS Optics

best flip up sights for ar 15 reviews, best ar15 flip up sights, best buis

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Many AR 15 rifles are built today with a flat top upper designed to accept optics. Some are even built with a gas block that simply has a flat rail on top, leaving the rifle with no front sight. Many people happily run optics-only rifles, but many people are also looking for the best AR 15 flip up sights.

Flip up sights give you the best of both worlds. Designed to fold out of the way and mount underneath a scope or red dot, flip up sights, or back up iron sights are meant to serve as a backup in case of optics failure, or to simply allow the rifle owner to switch back and forth between optics and iron sights at their leisure. There are a lot of choices for good sights. Some are made of modern polymer while others are an all metal construction. We take a look at 4 of the best flip up sights for AR 15 rifles below:

Magpul Backup Iron Sight

When I built my AR 15, this is the rear sight I chose. A Magpul Backup Iron Sight (BUIS) is another way of saying “best AR15 flipup sight.” The BUIS, like all Magpul products are built of a rugged modern polymer, and designed for harder use than anyone outside of the military is likely to put it through. Windage adjustable, and featuring two different sized apertures, this is probably the lightest, most reliable polymer flip up sight on the market right now. If you want a rugged sight from a name you know you can trust, these are the best flip up sights for you.

Install and Zero Magpul MBUS sights

SNIPER Brand Tactical Flip Up Sight

A low cost alternative to the Magpul, this is the best AR 15 flip up sight on a budget. Modern injection molding techniques help drive cost down, while still maintaining usability. While not built for high end use, for use on a casual plinking rifle or a low cost backup to your optics, it’s hard to go wrong with the Sniper flip up sight. Made of black polymer, adjustable for windage, and of course capable of being folded down when in use, this is the flip up sight to grab when you just need a basic, simple AR 15 flip up sight.

Sniper Flip-Up AR15 Sight Set from Sportsman's Guide

Troy Industries Front and Rear Flip Up Sights

As not all AR 15’s are built with any iron sights at all, sometimes you need to buy a full set of sights. Some of the best AR 15 flip up sights are made by well-known Troy Industries. These sights (see full specs) are precision made metal sights designed to last a lifetime or three. The rear sight is windage adjustable and features two different apertures, while the front sight adjusts for elevation. Both units fold down to an extremely low profile, making them an ideal set of backup iron sights to the optics of your choice.

Troy Industries Folding BattleSights

Green Blob Outdoors Flip Up Sights

A funny name with a fantastic design. No polymer here, Green Blob gives us another one of the best AR 15 flip up sights with aircraft grade aluminum construction, unique diamond shaped windage adjustable apertures, and elevation adjustable front sight. Sights are precision calibrated and matched as a pair to ensure maximum accuracy, and cost less than some single rear sights by themselves. Built for shooters who want an all metal set of flip up sights with a superior sight picture, the diamond apertures are easier to acquire than a standard round aperture. For price, construction and precision accuracy, it is hard to beat a set of Green Blob flip up sights.

Common Types of AR 15 Flip Up Sights

When looking for the best flip up sights for AR 15, most shooters look for one of four things. The first two are a choice between polymer and aluminum construction. Some people favor metal sights due to real or perceived matters of durability. Certainly when looking at cheaper polymer sights, durability can be an issue, but when considering high end brands like Magpul, there should be no question as to the quality or reliability of polymer sights. However, some people prefer metal sights, and there are certainly many options for them to choose from.

Other Considerations

The next consideration is if you need a single rear sight or both a front and rear sight. Many AR 15‘s are built with a flat top upper, but feature a standard front sight as part of the gas block. In that case, the choice is simple, and you only have to decide between metal or polymer. While in this case, an AR 15 is built primarily for optics and may never see backup irons installed, many people still choose to have a set on hand as it is fairly cheap insurance in case a red dot or scope fails.

Because flip up sights are designed to be a backup for optics, they all have a few things in common. Naturally they fold down, and the goal is to make the thinnest sight (which reduces the likelihood of needing higher than normal rings for mounting your scope over them) and typically they can also co-witness with a red dot if you so desire. Essentially, flip up sights are designed to mimic the features of standard AR 15 sights, while also being compact.

Once you’ve settled on the best flip up sights, it’s simply a matter of fastening it to your rail, right? Well, sort of. The beauty of a flip up rear sight is you can place it at the most optimal location on your upper, both for ideal eye relief, and to fit underneath your optic. As many Picatinny rails have numbered slots, once you figure out the ideal placement for your sight, you can take note of which number you have it on (I scratched that on the base of my sight) and can quickly replace it should you ever have to take it off. All in all, the best flip up sights for AR15 rifles are some of the most versatile iron sights you can get, and let you enjoy the flexibility of custom placed sights, and to back up your optics as well.

  • Owner of, Boyd Smith is a major handgun enthusiast, and although he owns Glocks, he prefers the revolving wheel type. His go-to guns are a Smith & Wesson 642 Performance Center for carry and a Ruger GP100 in the nightstand biometric safe (he has kids). He loads both revolvers with old-school 148-grain Federal Gold Medal .38 wadcutters. It’s OK if you think he’s a wimp. Email him.

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