Apex Optic Mount for FN MRD Pistols to mount RMR Footprint Optics

Factory optic-mount interface for FN MRD pistols. This mount replaces the factory cover plate and provides a direct, stable platform for optics using the RMR footprint (including Trijicon RMR, Holosun 407C/507C/508T, and similar). It solves the fitment gap between the FN Low Profile Optics Mounting System and standard RMR-pattern optics—no adapter plates, no MRD key inserts required. Screws arrive with high-temperature thread-locking patch pre-applied; no liquid thread locker needed.

Compatibility

• FN 509 series (all MRD-cut models)
• FN 509 Compact / Compact MRD
• FN 509 Tactical
• FN 509 Midsize / Midsize MRD
• FN 510 MRD
• FN 545 MRD
• FN Reflex MRD
• FN FNX-45 MRD
• FN FNS-9 / FNS-40 (MRD-cut variants)
• Does NOT fit non-MRD slides or optics using Delta Point Pro / Shield RMS / Docter footprint

Key Features

• Direct-fit to factory FN slide – no MRD key insert needed
• 6061-T6 aluminum construction, black anodized finish
• RMR footprint – accepts Trijicon RMR / SRO, Holosun 407C/507C/508T, Swampfox Justice, Vortex Viper (with included adapter plate, sold separately)
• Pre-applied high-temp thread-locking patch on all mounting screws
• Low-profile design – co-witnesses with factory suppressor-height sights
• Includes mounting screws and T10 Torx wrench

Install Difficulty: 2/5

Tools needed: T10 Torx driver (included), blue Loctite (optional – pre-applied patch is sufficient). Remove factory cover plate, place mount, torque screws to 15 in-lbs. No slide modification or gunsmith fitting required. Estimated time: 5–10 minutes.

FAQ

Will this mount let me co-witness with factory iron sights?

Yes – when used with FN factory suppressor-height sights (standard on 509 Tactical and MRD models). The mount sits at the same height as the factory cover plate, so your existing sight picture remains unchanged.

Can I use this with a Delta Point Pro footprint optic?

No. This mount is specifically machined for the RMR footprint. For DPP-pattern optics, you will need a separate adapter plate or a dedicated DPP mount.

Do I need to apply thread locker to the screws?

No. Each screw has a factory-applied high-temperature thread-locking patch. Torque to spec and let cure 24 hours before live fire. If you prefer additional security, a drop of blue Loctite 242 is compatible but not required.

Shipped from us within 1 business day. Covered by manufacturer warranty against defects in material or workmanship. Returns accepted within 30 days of delivery if unused and in original packaging.