FN 509M MRD 9mm Mid-Size Pistol 15+1 4" Optic Ready FDE

The FN 509M MRD delivers enhanced versatility for shooters demanding both compact carry dimensions and full-size performance capabilities. This mid-size striker-fired pistol bridges the gap between concealment and duty use with its 4-inch barrel and 15+1 capacity configuration.

What Makes This Different

The MRD (Modular optic Ready Design) platform sets this pistol apart from standard carry guns through its factory-machined optic cut and included mounting plates. The Flat Dark Earth PVD coating provides superior corrosion resistance compared to standard Melonite finishes, while the recessed crown barrel protects the rifling from damage during holstering and handling. This combination of features delivers professional-grade durability in a package sized for everyday carry.

Key Features

• Factory optic cut accepts popular red dot sights with included mounting plates
• 4-inch cold hammer-forged barrel with recessed crown for accuracy and protection
• Flat Dark Earth PVD coating on steel slide resists wear and corrosion
• 15+1 capacity with flush-fit magazine maintains compact profile
• Ambidextrous slide stop and magazine release accommodate all shooters
• Integrated Picatinny rail accepts tactical lights and laser modules
• Serrated steel slide provides positive grip during press checks and malfunction clearing

Field testing demonstrates consistent accuracy with the 4-inch barrel length providing excellent velocity retention across common defensive ammunition. The grip texture and ergonomic design maintain control during rapid-fire sequences, while the trigger system delivers a consistent break suitable for both precision shooting and defensive applications. Weather sealing protects internal components from moisture and debris infiltration during extended outdoor use.

Technical Specs

• Caliber: 9mm Luger
• Capacity: 15+1 rounds
• Barrel Length: 4 inches with recessed crown
• Overall Length: 7.4 inches
• Height: 5.5 inches
• Width: 1.35 inches
• Weight: 27 ounces (unloaded)
• Frame: Flat Dark Earth polymer with integrated rail
• Slide: Steel with Flat Dark Earth PVD coating
• Sights: Low-profile 3-dot system
• Trigger: Striker-fired with safety blade
• Country of Origin: USA

The 509M MRD represents FN's commitment to modular design philosophy, allowing users to configure the pistol for specific mission requirements. Professional armorers and serious shooters recognize the value proposition of factory optic cuts and premium coating systems. Current inventory levels make immediate availability possible for qualified purchasers.