The number of AR15 Back Up Iron Sights on the market has exploded over the past 10 years. I’ve had the opportunity to try a number of different models over the years. The problem with many of the designs on the market is they are too large, too complicated, and interfere with ideal mounting or the operation of the primary optics sighting systems on the rifle.
The Hahn Precision BUIS addresses all these concerns with a compact, functional, rugged design.
The body of the sight is machined from Aluminum billet and hard coat anodized. The aperture/sight tower is made from wire EDM’ed steel. The aperture diameter is 0.100″ and allows the shooter a good compromise between long range accuracy and close range speed. The aperture/sight tower is held folded and held up by spring tension. Deploying and stowing the sight is simple, there are no buttons to push or levers to fold out of the way, simply push the sight up or down. While the sight does not snap into place under its own power, it will not fold under recoil. If dropped on the sight it will fold to prevent damage.
The Hahn Precision BUIS is very low profile and fits underneath magnified optics, and only uses the rear most slot on a flat top upper receiver. It is also low profile in width by making use of the A1 style adjustment system. The sight stays zeroed unless deliberately moved. Another advantage to the A1 style adjustment system is there is not a large windage knob interfere with charging handle operation. Shooters with flip to the side magnifiers for red dots will particularly appreciate this. With the magnifier flipped to the side access to the charging handle can be much tighter with a large windage drum in the way, with the hahn sight the shooter can operate the charging handle normally. This feature alone is why I have gradually replaced all my BUIS with Hahn Precision units.
The Hahn Precision BUIS is a well thought out, quality manufactured unit and combines all the best features that a BUIS should have.