Modern defensive pistols must balance duty-grade durability with concealment-friendly ergonomics. For shooters who want a midsize platform with optics-ready capability and familiar striker-fired controls, this pistol checks those boxes while offering features that matter on the range and in a duty context.

FN 509M MRD The FN 509M MRD is built as a successor to FN’s FNS series and serves as a modern striker-fired duty and defensive pistol. It combines a concealment-friendly 4-inch barrel and shorter grip with an optic-ready slide and suppressor-height sights designed to co-witness with red dots via FN’s MRD adapter plates. Shop this product

Design and key features

The 509M MRD uses a polymer frame to keep weight down and resist corrosion, paired with 3-dot style luminescent sights for low-light reference. Ambidextrous controls and interchangeable backstraps let shooters tailor the grip profile to hand size and carry preference. The optic-ready slide accepts MRD plates for fast red-dot installation, and the included suppressor-height sights allow sighting over common mini‑red dots without modification.

Magazine capacity and finish

This model ships with two 15-round magazines and an all-black finish that reduces glare and presents a professional duty appearance. At a street price of $850.99, it positions itself competitively among midsize, optic-capable striker-fired pistols when comparing value-to-features.

Performance and handling

Expect a crisp striker-fired trigger feel consistent with FN’s design philosophy and a balance optimized for follow-up shots thanks to the shorter grip and 4-inch barrel length. The midsize footprint makes it practical for daily carry options while remaining controllable for range work and defensive drills. The MRD-ready slide shortens transition time to dot sighting and simplifies training for shooters moving from iron-sight systems.

View product details and pricing

Who should consider the 509M MRD

This pistol is aimed at users who want a service-capable striker-fired platform that’s compact enough for everyday carry but large enough to serve in training or duty roles. Law enforcement professionals, private security, and experienced civilian carriers who favor optics-ready versatility will find the feature set useful.

For current stock and to purchase directly from our shop page—where clicking through will take you to the retailer purchase option—please Check current availability

People Also Ask