
The FN 509 Full Size MRD is a duty-style 9mm pistol built for dependable personal protection, home defense, and training use. Its 4.5-inch cold hammer-forged stainless steel barrel features FN’s recessed target crown for long-term rifling protection and consistent accuracy. The full-size slide and frame add weight to help reduce felt recoil, while the enhanced grip texture and interchangeable backstraps support a secure, comfortable hold. The slide incorporates FN’s Low-Profile Optics-Mounting System for a compatible red dot sight and is paired with suppressor-height adjustable sights. Fully ambidextrous controls, aggressive slide serrations, a loaded chamber indicator, and a MIL-STD-1913 accessory rail provide practical handling and setup flexibility.
Key features
- Chambered in 9mm with a 10+1 capacity
- 4.5-inch cold hammer-forged stainless steel barrel with recessed target crown
- FN Low-Profile Optics-Mounting System for compatible red dot sights
- Suppressor-height adjustable sights for improved sight alignment with an elevated optic or suppressor
- Striker-fired semi-automatic action with integrated trigger safety
- Enhanced grip texture and interchangeable backstraps for control and fit customizationconversation
The FN 509 Full Size MRD combines full-size handling, optics-ready capability, and durable construction in a versatile 9mm defensive pistol.



