The FN 509 Midsize MRD is a striker-fired 9mm pistol designed for users who want a compact, duty-capable handgun with full-size handling characteristics. Its four-inch barrel and polymer frame provide a balanced combination of shootability and practical carry dimensions. This no-manual-safety model uses a trigger safety and includes interchangeable backstraps for a more personalized grip fit. The slide features the FN Optics Mounting System with plate adapters, allowing compatibility with a range of miniaturized red dot optics. Fixed 3-dot sights, front slide serrations, an integrated accessory rail, ambidextrous controls, and a loaded chamber indicator complete the practical configuration.

Key features

• 4-inch barrel offers a balanced blend of control and compact handling
• 10+1 capacity with two included 10-round magazines
• FN Optics Mounting System with plate adapters supports compatible red dot optics
• Striker-fired operating system with an integrated trigger safety and no manual safety
• Interchangeable backstraps help tailor the grip to the user's hand
• Fixed 3-dot sights support quick target acquisition in standard lighting conditions

The FN 509 Midsize MRD combines adaptable ergonomics, optics-ready performance, and dependable controls in a practical 9mm pistol.