The availability of affordable lasers, lights and optics make the AR-15 a viable firearm for many uses. It is easy to customize this reliable operating system for both indoor and outdoor uses, such as when a fight extends to outside the home. Today’s optics are especially useful with the onset of riflescopes designed for the .223 Rem./5.56 round.
However, optics can fail, and if you’re in the middle of a deadly attack, you need a backup plan. While one solution is to fall back to a handgun, if you have backup sights on your rifle, you can continue to utilize its available firepower.
There are different ways to utilize backup sights on a rifle—flip mounts, sights on top of optics and side-mounted sights, such as the XS Sight Systems XTI (Xpress Threat Interdiction). The XTI are angled-mounted sights that attach to the side Picatinny rail of AR-15 rifles. They are designed for the fast-target acquisition required of CQB.
I recently mounted a set of XTI sights to my AR for both CQB and as backup sights. They attached easily to the quad rail, but were a little harder to sight, as you have to made sure that you’re always holding the same sight picture with the rifle at an angle. Once sighted though, these sights worked well for close targets and out to farther distances. To swap to them, you only have to rotate the rifle about 45 degrees and take aim. My only complaint is that I would prefer them to be about an 1/8-inch higher for easier acquisition, even thought I understand the point of having them low is to prevent them from hanging up at an inopportune time.