FN’s 509 Midsize MRD: 4″ cold-hammer-forged barrel, black polymer midsize frame with Picatinny rail, MRD slide with FN Low-Profile Optics Mounting System (adapter plates included; no red dot), black co-witness iron sights and striker-fired trigger. FN lists about 7.4″ OAL, about 1.35″ width, about 5.2″ height and about 26.5 oz unloaded. Ships with two 10-round magazines. No factory optic — MRD optic-ready only. Manufacturer part number: 66100588.
Key features
- 9mm; 10+1; two 10-rd magazines
- 4″ barrel; ~7.4″ OAL; ~26.5–26.9 oz
- MRD Low-Profile Optics Mounting System (no optic)
- Co-witness iron sights
- Polymer midsize frame; Picatinny rail
- Striker-fired; ambi-friendly controls
Buying from PM Customs in Yukon
PM Customs is a licensed FFL in Yukon, OK, serving the Oklahoma City metro. Choose local pickup by appointment (generally Mon–Sat, 8 AM–4 PM), or have your FN 509 Midsize MRD shipped to your local FFL. You pick at checkout. Questions? Call 405-265-8955.
