FN 509 Midsize Tactical 9mm | 4.5″ Threaded

The FN 509 Midsize Tactical is a versatile, optics-ready midsize pistol chambered in 9mm with a 4.5″ threaded barrel and suppressor-height night sights. It ships with two magazines (a 15‑round and a 24‑round) and is built on a matte black polymer frame with a Picatinny rail for accessories. The pistol pairs well with compact red-dot micro‑reflex sights; a reliable option under $1,000 that matches the FN low-profile mounting system is the Holosun 507K series.

Typical applications for this platform include everyday carry in jurisdictions where midsize pistols are preferred and duty or range training where higher-capacity magazines and threaded-barrel capability are valuable.

Product Specifications

• Manufacturer: FN America / FN Herstal.
• Model: FN 509 Midsize Tactical (FN509M).
• Caliber: 9mm.
• Barrel length: 4.5 inches.
• Thread pattern: 1/2×28.
• Optic footprint: Multiple (FN Low-Profile Optics-Mounting System).
• Sights: Suppressor-height 3-dot night sights.
• Slide: Optic-ready, serrated with a long-wearing PVD finish in matte black.
• Frame: Matte black polymer frame with MIL-STD-1913/Picatinny accessory rail.
• Action type: Striker-fired semi-automatic.
• Magazines included: Two magazines (one 15‑round and one 24‑round as packaged).
• Number of magazines: 2.
• Additional features: Fully ambidextrous controls and interchangeable backstraps.
• Package contents: Two magazines, FN soft case, locking device, and owner’s manual.
• UPC: 845737015169.

The FN 509 Midsize Tactical provides a practical balance between concealability and capacity while offering factory features for optics mounting and suppressor compatibility. Its threaded barrel and suppressor-height sights make it suitable for shooters who need suppressor-ready capability or who run dedicated training sessions with higher-capacity magazines. The optics-ready slide and Picatinny rail allow modular accessory options without altering the pistol’s core ergonomics.

Related Videos: