The FN 509M Midsize Tactical is a semi-automatic 9mm pistol configured with a 4.5-inch threaded barrel, optics-ready serrated slide, and suppressor-height night sights. Its polymer frame, interchangeable backstraps, fully ambidextrous controls, and five included 10-round magazines support a versatile setup for duty, training, and responsible defensive applications.

The pistol uses a double-action-only operating system and features an FN Optics Mounting System for compatible optics. A 1/2×28 thread pattern, suppressor-height sights, and a black finish complete the configuration.

Key Specifications

• The pistol is chambered in 9mm for use with compatible 9mm ammunition.
• The barrel measures 4.5 inches and features a threaded configuration.
• The barrel uses a 1/2×28 thread pattern.
• The listed capacity is 10 + 1 rounds.
• The operating system is specified as double action only.
• The slide is optic ready and serrated for compatible sighting equipment and handling.
• The pistol includes suppressor-height 3-dot night sights.
• The frame is made from polymer and has interchangeable backstraps.
• The controls are fully ambidextrous.
• The bundle includes five 10-round magazines and an FN soft case.

With its optics-ready slide, threaded barrel, adaptable grip, and complete magazine package, the FN 509M Midsize Tactical provides a well-equipped platform for shooters who value practical configuration and consistent handling.