Apex Optic Mount Holoson 509T to SIG P320 with SIG-LOC Optic Cut

Description

This Apex Optic Mount provides a secure, precision-machined solution for mounting your Holosun 509T onto a Sig Sauer P320 slide equipped with the factory SIG-LOC optic cut. Designed specifically for the P320 Legion, M17, M18, and other models with this cut, this mount is built from a solid billet of steel with a durable Black Oxide finish.

The integrated rear sight is positioned directly in front of the optic. This dual-purpose design acts as a gas shield, deflecting blowback debris away from your Holosun’s objective lens. The result is noticeably cleaner glass between cleanings, reducing the time spent wiping down your optic at the range. This front-mounted rear sight is calibrated for a lower 1/4 co-witness (bottom 25% of the optic window), keeping your sight picture clear while still providing a reliable backup aiming reference.

Key Features & Specs:

• Integrated Gas Shield: The rear sight base functions as a blast deflector, channeling gas and debris away from the optic lens to maintain a clearer sight picture.
• Co-Witness Ready: The integrated rear sight co-witnesses in the bottom 25% of the Holosun 509T window. A tall front sight is included to achieve this co-witness. Two different front sight height options are available at checkout – select based on your specific barrel length.
• Factory LCI Compatible: Works seamlessly with the factory Loaded Chamber Indicator on M17/M18 models.
• Secure Mounting: Pre-applied thread locking patch on all screws. Torque to 20 in-lb for a rock-solid hold.
• Zeroed for Accuracy: Sights are regulated for point of aim / point of impact at 10 yards using 115 grain ammunition.
• Material & Finish: Machined from billet steel with a Black Oxide finish for long-term durability and corrosion resistance.

Fitment: This mount is designed exclusively for the Sig Sauer P320 slide with the SIG-LOC optic cut pattern. It securely mounts the Holosun 509T (all models) and replaces the need for a separate rear dovetail sight. The included tall front sight must be installed to achieve proper co-witness.

Important Note on Sighting: This version places the backup iron sight in front of the optic. If you prefer the rear sight positioned behind the optic (with a separate blast deflector block not visible through the window), that configuration is available separately. This mount is distinct from the Apex 112-018-PRO, which omits