XS Sights AR-15 Tritium Flip-up BUIS

XS Sights is well known for its rugged handgun sights. They also make rifle and shotgun sights, including a set of flip-up models for the AR-15. Let’s take a look at what you get with these US-made sights.

XS Sights AR backup sights are constructed from lightweight aluminum and stainless steel. They are finished with a matte black hard coat anodizing for enhanced resistance and longevity. They adhere to mil-spec dimensions, ensuring they securely lock into position on any standard 1913 Picatinny rail.

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The sights add minimal weight to your setup, weighing just 3.05 ounces. The rear sight offers versatile zeroing options: a notch for a quick 7-yard zero for close quarters, a small aperture for a precise 100-yard zero, and a large battle aperture for a wider field of view. The front post incorporates a vertical tritium stripe paired with a white outline for low-light visibility.

You can buy either the front or rear sight individually, or get them as a pair. Individually, the front sight assembly runs $172.99, while the rear sight goes for $146.99, and they run $349.99 for the pair. XS Sights are manufactured in Fort Worth, Texas.

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Installation and Use

Installation of the XS Sight’s backup irons is pretty straightforward. Just loosen the screw on the mount, place it on the rail where you want it, and tighten the screw back down. The sights are designed to flip rearwards towards the butt of the gun.

From the folded position, you can just flip the sights up when needed. Once open, they lock in place. To fold them back down, you depress the button on the side of the sights and manually fold them back into their stowed position.

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The rear sight has two flip-up options. The one option has a notch for fast, close engagements as well as a small peep designed for a 100-yard zero. The other option is a big A2-style peep. Adjustment on the rear doesn’t require tools and is easily accomplished by the windage dial on the right side of the sight. The front sight does use the included front sight tool to adjust elevation.

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Construction is quite solid, and all parts move smoothly and lock up tightly. The sights line up cleanly and offer an excellent sight picture. In dim light, the tritium in the front post allows you to still find your sights.

Backup and General Use

I mounted the XS flip-up sights on my CMMG SBR. I ran it without optics for testing. In addition to their obvious use as backup sights, they’re also a nice option if you want to run a streamlined build. You can fold the sights down for storage, and in use, these are as good as any irons I’ve used. While geared as AR sights, these should work on any firearm with a Picatinny rail.

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I’ll concede that XS’s backup irons aren’t the least expensive backup sight option in the market. But, they’re a top-quality, US-made product, with a tritium front. You won’t find those features with many of their competitors. If you need a top-tier set of backup sights or a compact set of stand-alones, then it’s worth giving XS Sights AR-15 Tritium Flip-up BUIS a look.