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

Description

This Apex Optic Mount solves a specific problem for shooters running a Holosun 509T on a Sig Sauer P320 with the SIG-LOC optic cut. If you train or carry in Arizona’s high-dust, high-heat environment, you already know how fast an optic lens can get fouled. This mount is built to handle that, while keeping your backup iron sights functional and your setup reliable.

Machined from a single billet of steel with a Black Oxide finish, this mount is tough enough for desert use and suppressor-friendly. It fits the P320 Legion, P320 M17/M18, and any other P320 slide with the SIG-LOC optic cut. The mount secures the Holosun 509T directly to the slide, with a thread locking patch pre-applied to the screws. Torque to 20 in-lb and you’re set.

Integrated rear sight and gas shield

• Built-in rear sight sits in front of the optic, acting as a gas shield. This deflects debris and carbon blowback away from the objective lens, keeping your glass cleaner between range sessions or after a string of suppressed fire.
• The integrated rear sight co-witnesses in the bottom 25% of the optic window. A tall front sight is included with the mount—select your sight height package based on your barrel length. Two options available.
• If you prefer a rear sight behind the optic, that version includes a blast deflector that stays out of your sight picture. Both setups keep your optic functioning in bright sun and dusty conditions.

Compatibility and specs

• Direct fit for P320 slides with SIG-LOC optic cut
• Works with factory Loaded Chamber Indicator on M17/M18 models
• Sights regulated for point-of-aim equals point-of-impact at 10 yards with 115 grain ammunition
• No need to install a separate rear sight—saves time and keeps your slide clean
• Price: $135

Whether you’re shooting suppressed in the heat or carrying in dusty conditions, this mount keeps your Holosun 509T locked in and your sight picture clear. It’s a direct upgrade for anyone running a P320 with a SIG-LOC cut who wants a gas shield, co-witness irons, and a mount that holds zero under hard use.