The FN 509 Midsize MRD pistol in 9mm and black finish (brand part no. 66100588) trims the full-size 509 down to a midsize frame while keeping the mini red dot optics mounting system, giving shooters a more concealable platform with red-dot compatibility. FN America builds the pistol with a 4-inch barrel and black co-witness iron sights that align with a mounted red dot. The trigger runs with no manual safety, and two 10-round magazines plus a soft pistol case ship with the pistol. Among optic-ready semi-auto handguns, this 509 Midsize configuration favors shooters in capacity-restricted states who still want the 509 platform.

Key Specifications

• The chambering is 9mm.
• The capacity is 10 rounds.
• The barrel measures 4 inches.
• The slide is black steel, serrated, with black co-witness iron sights.
• The trigger runs with no manual safety.
• Two 10-round magazines and a soft pistol case ship with the pistol.
• The unloaded weight is 26.9 ounces.
• The rifling twist rate is 1:10-inch.
• The action is semi-automatic, cycling a fresh round into the chamber with every trigger pull.

Frequently Asked Questions

Do the iron sights co-witness with a red dot? Yes, the co-witness iron sights align with a mounted optic.

What comes included with this pistol? Two 10-round magazines and a soft pistol case.

Buy the FN 509 Midsize MRD Pistol, 10-Round

The full-size 509 trimmed to a midsize frame while keeping the mini red dot optics mounting system is exactly what this FN 509 Midsize MRD Pistol delivers.