The FN 509 Compact in FDE is a striker-fired 9mm pistol with a 3.7-inch barrel, 6.8-inch overall length, and 1.6 lb weight. Capacity is 12+1 or 15+1 depending on magazine, with a 24-round extended option also available. The frame is FDE polymer with interchangeable backstraps. Sights are HiViz front with low-profile rear. The flat-faced precision trigger and loaded chamber indicator are standard. 
 

Key Specifications 

• Brand: FN America 
• Model Name: FN 509 Compact 
• Caliber: 9MM Luger (9X19 PARA) 
• Action: Striker Fired 
• Capacity: 24 Rounds (also available as 12+1/15+1) 
• Barrel Length: 3.7 inches 
• Weight: 1.6 lbs. 
• Sights: Open Notch with HiViz Front and Low Profile Rear 
• Finish: Flat Dark Earth (FDE) 
   

Detailed Features 

Interchangeable backstraps allow grip customization without aftermarket parts. The flat-faced trigger provides a consistent pull surface and a clean break. The loaded chamber indicator gives a tactile and visual check without cycling the slide. At 6.8 inches overall and 1.6 lbs, the 509 Compact carries well for its capacity class. 
 

Target Audience 

Concealed carry permit holders who want higher capacity in a compact frame, and sport shooters who need accuracy and reliability in a smaller package.

The FN 509 Compact FDE is well-regarded for its ergonomics -- the interchangeable backstraps and grip texture get consistent praise, and the flat-faced trigger draws positive comments for its feel and clean break. The 24-round magazine capacity option is a standout feature that owners frequently cite as a deciding factor.

On the critical side, the gun runs slightly larger than some compact pistols in its class, and owners with smaller hands or strict concealment requirements note the size difference compared to micro-compacts. The weight at 1.6 lbs is manageable but at the top of the compact category. Holsters and accessories specific to this model can be harder to find than for more established platforms. Pricing lands on the higher side of the compact 9mm market.