Apex Optic Mount for RMSc/507K – FN 509

Overview

Apex Optic Mount for RMSc/507K – FN 509 by Apex Tactical. Fits FN.

Available for delivery across the United States.

The Apex Optic Mount is a direct-fit solution for mounting a Shield Sights RMSc or Holosun 507K red dot to your FN 509 pistol. Designed specifically for the FN Low Profile Optics Mounting System™, this mount eliminates guesswork and ensures your optic sits securely on the slide.

Machined from a single billet of steel and finished with a black oxide coating, this mount holds up against humidity, salt spray, and daily carry sweat. In Florida’s coastal environment, corrosion resistance is not a luxury—it is a necessity. The black oxide finish provides a durable, low-glare surface that resists rust without adding unnecessary bulk to your setup.

Key benefits for your EDC:

• Secure optic fitment: The mount is precision-machined to interface with the FN Low Profile Optics Mounting System™ only. It prevents shifting or loosening under recoil, keeping your dot zeroed when you need it most.
• Simple installation: For the RMSc optic, use the “514” screws that came with your FN 509 Tactical or MRD model. For the Holosun 507K, use the screws included with this mount. No filing, no adapters, no modifications required.
• Low-profile design: The mount sits flush with the slide profile, allowing you to maintain a clean draw from a holster without snagging on clothing or gear.
• Steel construction: Unlike aluminum mounts that can deform under heat or impact, the billet steel construction provides a rigid foundation that holds zero even after hundreds of rounds.

Specs & fitment notes:

• Compatible with: FN 509 pistols equipped with the FN Low Profile Optics Mounting System™ (MRD cut slides).
• Optic compatibility: Shield Sights RMSc and Holosun 507K (including the 507K X2).
• Material: Billet steel with black oxide finish.
• Mounting screws: Included for 507K; use factory FN “514” screws for RMSc.
• Price: $65

This mount is built for shooters who carry daily in humid, salt-air conditions. It keeps your optic locked down without adding height or weight that compromises concealment. Whether you are running drills at the range or carrying on the beach, the Apex Optic Mount gives you a reliable mounting platform that stays put.

Why this matters for your carry setup: A loose optic can shift your point of aim at the worst possible moment. The Apex mount uses a steel-to