FN 66100383 509T | 9mm | 4.5″ Threaded Barrel | FDE

The FN 509 Tactical (part number 66100383) is an optics-ready striker-fired pistol built on FN’s 509 platform with a 4.5-inch cold hammer-forged stainless steel threaded barrel and Flat Dark Earth finish. It features FN’s Low-Profile Optics Mounting System and suppressor-height night sights, plus an enhanced grip texture and MIL-STD-1913 accessory rail for practical mounting options. The pistol is appropriate for duty/service and competition/practical shooting, and works well as a host for a suppressor when local laws permit. For an optic under $1,000 that pairs well with this platform, consider a Holosun 507K or similar compact red dot that co-witnesses with suppressor-height sights.

Product Specifications

• The UPC is 845737009144.
• The manufacturer is FN America / FN Herstal.
• The model is listed as 509 Tactical (66100383).
• The caliber is specified as 9mm.
• The barrel length is 4.5 inches with 1/2×28 threads.
• The action is Semi-Auto.
• The frame material is Polymer with a Picatinny rail.
• The finish and grip color are Flat Dark Earth.
• The optic interface is listed as Multiple via the FN Low-Profile Optics Mounting System.
• The sights are described as Suppressor-height night sights.
• The thread pattern is 1/2×28.
• The weight is listed as 27.9 oz.
• The overall length is 7.9 inches.
• The slide is described as Optic Cut / Serrated Stainless Steel.
• The pistol ships with a FN soft case and interchange-able backstraps.

This Tactical variant brings the core 509 features in an optics-ready chassis with a threaded barrel and night sights for low-light use. Its robust slide and FN optics mount make it a flexible choice for shooters who want a modern optics-capable pistol with a full-size grip and accessory rail. The platform’s controllable ergonomics and optics compatibility suit range use and practical competition applications.

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