I’ve had my primary AR-15 for about 5 years and its gone through many iterations of optics. I’ve tried the standard carry handle sights, Eotech 512, Millett DMS-1, and now finally what I consider to be the best of all worlds: Eotech 517, Primary Arms Deluxe 3x Magnifier, Larue LT755(T) Flip-to-Side mount and Troy BUIS.

The Eotech 512 that I previously had was great, but even at 50 yards, I was shooting 6″+ groupings. The Millet DMS-1 brought those grouping WAY in with the 4x magnification, but it was heavy, didn’t seem extremely durable, required a lot of eye relief and while it could be dialed down to 1x, it wasn’t a true 1x where it was easy to keep both eyes open. The DMS-1 reticle was also hard to see in sunlight.

The Eotech 517 has a built in 7mm riser, so you can get a 1/3 cowitness with your BUIS, helping the reticle clear the front sight post. The riser also allows you to push the optic forward and it overhangs the front rail (without touching it). The Larue mount is extremely solid in both positions, the Primary Arms glass is very clear and the 3x magnification makes for very accurate and consistent shots. Larue makes two LT-755 mounts, if you’re going to align a magnifier with a standard Eotech (like the 512), get the (S)hort version. If your Eotech has the built in riser (like the 517 or 557) get the (T)all model.