FN 509M T 9mm 4.5in Holosun Threaded

The FN 509M T is a midsize, optics-ready semi-automatic pistol designed for range use, duty applications, and suppressor-equipped configurations. Its combination of a 4.5-inch threaded barrel and factory-mounted Holosun 407C optic supports sighting setups commonly used for training and operational tasks.

Constructed with a polymer frame and a steel slide, the pistol pairs durable materials with ergonomic controls and interchangeable backstraps to accommodate a range of hand sizes. The cold hammer-forged stainless steel barrel features a recessed target crown and a 1/2×28 threaded muzzle to accept muzzle devices and suppressors where legally allowed.

Key Specifications

• The caliber is 9mm.
• The action is Semi-Auto.
• The barrel length is 4.5 inches.
• The magazine capacity is 10 rounds.
• The number of magazines included is 2.
• The included optic is a Holosun 407C.
• The muzzle thread pattern is 1/2×28.
• The frame material is Polymer.
• The weight is 27.9 oz.
• The finish is Black.

State Restrictions: This firearm is not available for direct shipment to California and is not for sale to Illinois (PICA).

The FN 509M T 9mm delivers optics-ready performance with a threaded barrel and factory red dot, making it suitable for shooters seeking a versatile midsize tactical pistol for range and professional use.