
| Brand | Other |
| SKU | — |
| UPC | — |
| Grip | Polymer with interchangeable backstraps |
| Action | Semi-Automatic |
| Finish | Black |
| Sights | Standard Sights |
| Weight | 27 ounces |
| Capacity | 17+1 |
| Grip Safety | No |
| Optic Ready | Yes |
| Barrel Length | 4.5 inches |
| Manual Safety | No |
| Overall Length | 7.9 inches |
| Trigger Safety | Yes |
| Caliber / Gauge | 9mm |
| Threaded Barrel | No |
| Magazines Included | 2 |
| Ambidextrous Safety | No |
| Condition | New |
Firearms ship to the FFL dealer you name at checkout. Price and stock are re-checked live when you order.
The FN 509 Fullsize MRD is a duty-style 9mm pistol designed for dependable performance in personal protection, home defense, and professional applications. Its striker-fired operating system provides a consistent trigger pull, while the 4.5-inch cold hammer-forged barrel features FN's recessed target crown to help protect the rifling and preserve accuracy. The polymer frame and interchangeable backstraps support a secure, customizable grip, and the slide's textured profile helps provide positive handling with reduced felt recoil. The FN Low Profile Optics Mounting System makes the pistol ready for a compatible miniature red dot sight while retaining its fixed three-dot sights for a practical co-witnessing setup.
The FN 509 Fullsize MRD combines full-size handling, optics-ready capability, and adaptable ergonomics in a dependable 9mm pistol.