Nighthawk Custom IOS (Interchangeable Optic System)

The Nighthawk Custom Interchangeable Optic System (IOS) is widely considered the best optic mounting solution for the 1911 platform. Nighthawk machines a deep tapered dovetail into the rear of the slide, and interchangeable billet steel plates slide onto this dovetail. A steel cross-pin retains each plate, backed by a set screw that carries no mechanical load — the dovetail absorbs all recoil forces. This design eliminates the plate-to-slide screws that are the most common failure point on adapter-plate systems like Springfield AOS and Glock MOS. The deep cut also allows standard-height front sights to co-witness through the optic window, avoiding the need for suppressor-height sights. Available on new Nighthawk builds as a factory option and retrofittable to most existing 1911s regardless of brand. Turnaround for retrofit installations is approximately six weeks. Plates are $150 each and available for Trijicon RMR, SRO, Shield RMSc, Holosun 509T, Aimpoint ACRO, Leupold DeltaPoint Pro, and Vortex Viper footprints. An iron-sight plate with a standard Novak rear sight cut is also available for switching back to irons.