C&H PLT FN 509 TO HOLO 509T

Description

The C&H Precision adapter plate is built for FN 509, FN 510, and FN 545 V4 MIL/LEO owners who want to mount a Holosun 509T without having their slide milled. The 509T uses a footprint that does not correspond to the factory optics cut on these pistols, so a purpose-made adapter is the practical path to a secure, repeatable mount. This plate closes that gap with a direct mechanical interface, no shimming or improvisation required.

The plate itself is machined from mild steel and finished with electro-deposition paint in black, a process that deposits coating uniformly across all surfaces, including recesses, for consistent corrosion resistance. All mounting hardware supplied with the plate is stainless steel, which resists the galvanic corrosion that can develop when dissimilar metals are in prolonged contact. Three 6-40 x .3125 M3H plate-mounting screws are included. Because the hardware is standard, replacements are available independently if a screw is damaged during installation or a later re-zero — the plate itself does not need to be replaced.

C&H Precision produces these plates at their facility in Richmond Hill, Georgia on HAAS CNC machines. Each plate is checked before it ships. The tight-tolerance machining matters here because optic height and cant relative to the bore are fixed at the plate, and any slop in the fit translates directly to a less stable zero. C&H recommends dry-fitting all components before final installation, particularly relevant given that tolerance stacking across the slide, plate, and optic can vary unit to unit. Iron sight compatibility will depend on your specific slide cut and the height of the 509T once mounted; C&H’s support team can advise on co-witness options for your configuration.