FN 509C MRD 9mm | 3.7″ Barrel | FN 66100571

The FN 509C MRD is a compact, optics-ready 9mm striker-fired pistol designed to deliver full-size performance in a smaller footprint. It ships with FN’s Low-Profile Optics Mounting System that accepts a wide range of miniature red-dot sights; a robust option under $1000 that pairs well is the Holosun 507C. The pistol’s compact dimensions and modular controls make it suitable for concealed carry and range training.

Product Specifications

• The caliber is 9mm.
• The barrel measures 3.7 inches.
• The action is a semi-automatic, striker-fired system.
• The frame is constructed from polymer with replaceable steel frame rails.
• The slide is an optic-ready, serrated steel slide finished in black.
• The optics interface is the FN Low-Profile Optics Mounting System (multiple footprints).
• The pistol includes co-witness iron sights compatible with the optics mount.
• The firearm includes one 12-round and one 15-round magazine.
• The overall length is 6.80 inches.
• The barrel is cold hammer-forged stainless steel with a recessed target crown.
• The package includes a soft FN pistol case, owner’s manual, and locking device.
• The finish is matte black.
• The pistol features fully ambidextrous controls for left- and right-handed shooters.
• The slide and frame include an integrated MIL-STD-1913 accessory rail for lights or other accessories.
• UPC: 845737010881.

This compact member of the FN 509 family balances concealability and controllability while offering broad optics compatibility through FN’s low-profile mounting system. Its striker-fired operation, interchangeable backstraps, and included dual magazines make it a practical choice for shooters who want a compact pistol that adapts to different hands and carry setups. The optic-ready slide and quality barrel work together to support consistent performance at the range or in everyday carry roles.