The BAD-BSM is an improved replacement BRACKET & SCREW designed and engineered to meet the rigorous demands of the MATECH B.U.I.S. 600 Meter Backup Iron Sight that is current issue to US Military forces, NSN 1005-01-484-8000, P/N 12996812.
The Matech backup sight is one of the best B.U.I.S. (Back Up Iron Sight) available. It's one of the few B.U.I.S. that has an elevation adjustment. It is also readily available and affordable. Based on user requests, input, and feedback, we have sought to make a great backup sight better.
The original screw has an over sized Allen head. This aspect, in conjunction with the small diameter and relatively weak screw, it tends to over torque, which resulting the recoil screw snapping in two.
We have strengthened the mounting screw, in our tests, the factory screw snapped at 30 inch-pound, the screw we selected, a Grade 8 plus, broke between 45 and 52 inch-pound. The Allen head on our screw is smaller to reduce the likelihood of over torque.
In addition, the mounting bracket itself has been redesigned. The bracket is counter bored to reduce the protrusion of the screw. The section that interfaces with the sight is twice as thick as the factory clamp (1.25mm vs. 2.60mm).
The retrofit clamp is CNC machined from solid 1080 carbon bar stock steel and manganese phosphate plated.
The retrofit clamp is cut to a tight tolerance. It will fit Mil-Spec. receivers. On receivers with tolerances on the plus side, both the factory and our retrofit clamp will cant slightly, this is due to the Matech's clamp being somewhat unique design, however, this is cosmetic only, as the sight is secure and does not move on the receiver.