The FN 509C Compact is a striker-fired 9mm pistol in black with a 3.7-inch cold hammer forged barrel, 15-round capacity, and a 6.8-inch overall length. Weight is 25.5 oz (1.6 lbs). The polymer frame keeps the carry weight reasonable, and the low-profile sights with a high-viz front dot work across typical lighting conditions. 
 

Key Specifications 

• Brand: FN America 
• Model: 509C 
• Caliber: 9MM Luger (9x19 Para) 
• Action: Striker Fire 
• Capacity: 15 Rounds 
• Barrel Length: 3.7 inches 
• Overall Length: 6.8 inches 
• Weight: 25.5 oz (1.6 lbs) 
• Sights: Low-profile, High-Viz front dot 
• Finish: Black 
   

Detailed Features 

The cold hammer forged barrel adds durability and contributes to consistent accuracy over a long service life. The striker-fired mechanism delivers an even trigger pull that suits fast follow-up shots. Interchangeable backstraps let you adjust grip fit for different hand sizes. 
 
The optics-ready slide accommodates common red dot footprints if you prefer a mounted optic. The accessory rail on the frame accepts lights and lasers without modification. At 15+1 rounds in a 6.8-inch package, the 509C offers solid capacity for a compact pistol.

The FN 509C Compact 9mm draws consistently positive feedback on ergonomics and performance, with a few areas that generate debate.

Grip comfort and control come up often -- the design suits a range of hand sizes and the gun handles well even in compact form. Accuracy at close and moderate distances is a recurring strength. Reliability gets positive marks across multiple ammunition types with few reported malfunctions.

The accessory rail and optics-ready features are well received by shooters who want to customize their setup with lights, lasers, or red dots.

On the critical side, some users find the 509C larger or heavier than other compact options, which makes it less practical for deep concealment. The trigger gets mixed reviews -- some shooters like it, others find it heavier or with a longer reset than they prefer. Pricing is a recurring debate, with buyers split on whether the FN build quality justifies the premium over competitors.