C&H PLT SIG P320 RX/AXG TO HOLO 509T

Description

The C&H Precision adapter plate for the SIG P320 RX, Pro Series, and AXG exists to solve a specific problem: the Holosun 509T uses a footprint that does not correspond to the factory optic cut on these slides, so without a bridge plate, the optic simply cannot mount. This plate closes that gap, letting you run a 509T on a slide that would otherwise be incompatible.

The plate is machined from steel, which matters here because the 509T is a full-enclosure optic with more mass than a typical mini red dot. A steel substrate distributes the recoil impulse across a harder, less deformable surface than aluminum would provide, reducing the risk of the mounting interface working loose over a service life of sustained firing. The finish is an Electro Deposition Paint process, which coats internal geometry as evenly as external surfaces and gives the steel meaningful corrosion resistance without adding dimensional bulk. Stainless steel mounting hardware is included, so the fasteners themselves won’t corrode and seize against the plate over time.

This plate is designed for P320 variants that retain their rear sight when the factory cover plate is removed — meaning the slide already has a fixed rear sight separate from the optic cover. It is not compatible with the 509T-RD ACSS Vulcan variant of the optic. If you are unsure whether your specific P320 variant qualifies, the slide’s rear sight arrangement is the detail to check before ordering. Replacement mounting hardware is available separately, so a stripped screw does not mean replacing the entire plate.