The FN 509C Compact is a striker-fired 9mm pistol in matte black with a 3.7-inch cold hammer forged barrel and 10+1 capacity. Total length is 6.8 inches and weight is 1.59 lbs (25.50 oz). The HiViz front sight pairs with a low-profile rear. 
 

Key Specifications 

• Brand: FN 
• Model: 509C 
• Caliber: 9MM Luger (9X19 Para) 
• Action: Striker Fire 
• Capacity: 10+1 Rounds 
• Barrel Length: 3.7 inches 
• Weight: 1.59 lbs (25.50 oz) 
• Sights: HiViz Front / Low Profile Rear 
• Finish: Matte Black 
   

Detailed Features 

The striker-fired mechanism delivers uniform trigger pull and removes the need for an external hammer or manual safety engagement, which simplifies operation under stress. Textured black grips with interchangeable backstraps let you adjust the fit to your hand size. Cold hammer forging produces a durable bore with a smoother surface that holds accuracy longer than button-rifled alternatives. 
 
At 6.8 inches overall and 1.59 lbs, the 509C fits comfortably under a cover garment while handling closer to a full-size pistol in terms of recoil management. The 3-dot HiViz/low-profile sight combination aids fast target acquisition.

The FN 509C Compact in matte black gets a positive reception overall with a few consistent criticisms.

Users frequently mention the ergonomics as a strong point -- the grip fits comfortably and control during shooting is good. Reliability comes up often: the gun runs cleanly across a variety of ammunition, making it a trusted carry choice. Accuracy draws praise too, with tight groups reported at typical range distances. The modular design -- different backstraps, optics-ready options -- appeals to those who like to configure their setup.

On the critical side, some users find the 509C larger and heavier than other compact options, especially compared to ultra-compact designs. Trigger feel is divisive: plenty of shooters like the pull, but others find it heavier or less crisp than they prefer, prompting conversations about aftermarket triggers. Pricing relative to competitors comes up regularly, with split opinions on whether the quality justifies the cost. Holster and aftermarket accessory availability is narrower than for more dominant platforms.