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

This optic mount provides a direct-fit solution for attaching RMR-footprint optics to FN MRD-pattern slides. It eliminates the fitment gap between the factory FN Low Profile Optics Mounting System™ and the Trijicon RMR/SRO, Holosun 407C/507C/508T, or any optic sharing the same bolt pattern. The mount solves the instability and height-over-bore issues that arise when using adapter plates or shims with non-Shield-pattern optics on these slides.

Compatibility

• FN 509 series (MRD-cut slides)
• FN 509 Compact / Midsize / Tactical
• FN 509 LS Edge
• FN 509 CC Edge
• FN Reflex (MRD-pattern slides)
• FN Five-seveN MRD
• RMR-footprint optics: Trijicon RMR/SRO, Holosun 407C/507C/508T/507Comp, Swampfox Justice/ Kraken, Vortex Viper/Venom (with sealing plate), Leupold DeltaPoint Pro (with adapter plate, not included)

Key Features

• Direct mount to factory slide – no MRD Key Insert or adapter plate required
• Preserves factory iron sight plane with co-witness capability
• Pre-applied High-Temperature Thread Locking patch on all screws – no liquid thread locker needed
• CNC-machined 7075-T6 aluminum, black anodized finish
• Maintains slide profile for holster compatibility

Install Difficulty: 2/5

Basic hand tools required: Torx T10 driver (for factory cover plate screws), Torx T8 or T15 (for optic screws, depending on optic brand). Remove factory cover plate, position mount on slide, torque screws to 15-18 in-lbs. Mount optic per manufacturer specs. No fitting, filing, or slide modification needed. Install time under 10 minutes.

FAQ

Will this work with a Holosun SCS or EPS?

No. The SCS and EPS use the Holosun K-footprint (Shield RMSc pattern), not the RMR footprint. This mount is RMR-spec only. For K-footprint optics on FN MRD slides, use the separate Apex K-Footprint Optic Mount.

Do I need to remove the rear sight?

No. This mount replaces only the factory optic cover plate. The rear sight remains in place and can be co-witnessed through the optic window (lower 1/3 co-witness with standard-height factory sights).

Will this work on a non-MRD FN slide?

No. This mount requires the factory MRD optic cut. Standard FN slides without the low-profile mounting system cannot accept this mount without slide milling.

Ships same business day if ordered before 2 PM EST. Backed by Apex’s limited lifetime warranty against manufacturing defects. All mounting hardware included.