The FN 509 MRD-LE in 9mm (brand part no. 66-101287LE) is a full-size striker-fired duty pistol with an optic-ready slide, tritium night sights and no manual safety. FN cuts the slide for its Low-Profile Optics Mounting System, which fits most miniature red dots, and ships four mounting plates in the box. A hammer-forged, target-crowned 4-inch barrel and a flat-face trigger that breaks cleanly give the pistol its accuracy. The package includes three 17-round magazines and three interchangeable backstraps, so it is ready for duty, home defense or range work out of the case.

Key Specifications

• The chambering is 9mm, the standard duty and training cartridge with wide ammunition choice.
• Barrel length is 4 inches, a hammer-forged, target-crowned barrel with a polished chamber and ramp.
• The pistol is shipped with three 17-round magazines, so a full load plus two spares are in the box.
• 3-dot tritium night sights are fitted, and they co-witness with a mounted red dot for low-light aiming.
• The slide is optic ready with FN’s Low-Profile Optics Mounting System, which fits most miniature red dots.
• Four MRD mounting plates are included, so a compatible optic can be fitted without buying an adapter.
• The pistol has no manual safety, relying on a drop-safe, duty-rated fire control group.
• The trigger is a flat-face design that breaks at 90 degrees, with a pull of 4.5 to 6 pounds.
• Three interchangeable backstraps fit the grip to different hand sizes and improve sight recovery.
• The pistol weighs 27 ounces and measures 7.4 inches overall, a full-size platform that stays controllable.

Frequently Asked Questions

Does the FN 509 MRD-LE have a manual safety? No. This configuration has no manual safety. FN builds it around a drop-safe, duty-rated fire control group and a flat-face trigger.

What red dots fit the FN 509 MRD-LE? FN’s Low-Profile Optics Mounting System fits most miniature red dot sights. The pistol ships with four MRD mounting plates, and the tritium night sights co-witness with a mounted optic.

What comes in the box? FN lists three 17-round magazines, three interchangeable backstraps, four MRD mounting plates, an owner’s manual, a locking device and an FN ballistic case.

Buy the FN 509 MRD-LE 9mm Pistol

A duty-grade pistol with night sights, an optic-ready slide and three magazines is a complete package for serious defensive use. See more semi-auto handguns from our catalog, then order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.