Description
The FN 66100572 509C MRD Compact Frame 9mm Luger 10+1 3.70″ Black Recessed Target Crown Steel Barrel, Black PVD Optic Ready/Serrated Steel Slide & Polymer Frame w/Picatinny Rail, Ambidextrous is the compact powerhouse that punches well above its weight. This factory-new pistol delivers full-size FN reliability in a carry-friendly package, with an optics-ready slide, aggressive texturing, and a flat-faced trigger for faster, more consistent shooting. Per FN America specs, the recessed target crown barrel enhances accuracy while the black PVD coating protects against wear and corrosion.
| Manufacturer | FN America |
|---|---|
| Model | 509C MRD Compact (Part #66100572) |
| Caliber | 9mm Luger (9×19) |
| Capacity | 10+1 rounds |
| Barrel Length | 3.70 inches |
| Barrel Type | Recessed target crown, steel, black PVD |
| Slide | Black PVD, serrated front & rear, optic-ready |
| Frame | Black polymer with Picatinny rail |
| Finish | Black PVD (slide), black polymer (frame) |
| Weight | Approx. 24.5 oz (empty, per manufacturer specs) |
| Sights | Black co-witness iron sights (front & rear) |
| Safety | Ambidextrous slide stop, reversible magazine release |
| Condition | New |
Key Features
- FN Low-Profile Optics Mounting System — Directly mounts over 10 popular red dot footprints without aftermarket plates. The system sits low enough to co-witness with the included black iron sights, so you stay on target even if the dot fails.
- Flat-Faced Trigger with Improved Texturing — The flat trigger provides a consistent finger placement and a cleaner break. Aggressive stippling on the frame and slide serrations give you a secure grip in wet or gloved conditions.
- Fully Ambidextrous Controls — Slide stop and magazine release are reversible for left-handed shooters. This gun works equally well for righties, lefties, and shooters who transition between hands.
- Recessed Target Crown Barrel with Black PVD — The recessed crown protects the rifling from impacts and holster wear. Black PVD coating resists holster wear and corrosion far better than standard bluing or nitride.
Who It’s For
The FN 509C MRD is built for the daily carrier who demands optics-ready capability without the bulk. It’s ideal for plainclothes officers, security contractors, and civilian concealed carriers who train hard and shoot often. If you want a compact 9mm that runs with top-tier red dots and still fits in a compact holster, this is your pistol.
Pros & Cons
- Pro: Factory optics cut with 10+ plate compatibility — no gunsmith needed.
- Pro: Ambidextrous controls make it truly universal.
- Pro: Recessed target crown barrel improves accuracy and longevity.
- Con: The aggressive frame texture can be rough against bare skin under a shirt — a T-shirt or undershirt solves it.
How It Stacks Up
| Feature | FN 509C MRD | Zev Technologies OZ9 Compact | Agency Arms AOS Glock 19 |
|---|---|---|---|
| Optic system | FN Low-Profile (10+ plates) | Zev RMR cut (limited plates) | Agency AOS (swap plates) |
| Barrel | Recessed target crown, PVD | Threaded, match-grade | Standard Glock barrel |
| Trigger | Flat face, 5.5–6.5 lb pull | Adjustable flat trigger | Flat face, 4.5–5.5 lb pull |
| Ambidextrous | Full ambi slide stop & mag release | Ambi slide stop only | Ambi slide stop only |
| Price | $742.54 (street) | $1,100+ | $900+ |
The FN 509C MRD undercuts both the Zev and Agency options in price while offering the widest optic compatibility and true ambidextrous controls. The Zev has an adjustable trigger and threaded barrel for suppressor use, but you’ll pay nearly 50% more. The Agency AOS is a solid Glock upgrade, but it lacks the recessed crown barrel and full ambi controls.
FAQ
What optics are compatible with the FN 509C MRD?
The FN Low-Profile Optics Mounting System includes adapter plates for more than 10 optics, including Trijicon RMR/SRO, Leupold DeltaPoint Pro, Holosun 407C/507C/508T, Sig Sauer Romeo1Pro, Shield RMS/SMS, and Docter/Noblex. Check the included plate chart for the full list.
Does the FN 509C MRD come with a threaded barrel?
No, this model (part #66100572) comes with a 3.70-inch recessed target crown steel barrel with a black PVD finish. It is not threaded. FN offers a separate threaded barrel version if you need suppressor compatibility.
Can I use standard FN 509 magazines in the compact frame?
Yes. The 509C MRD takes all FN 509-series magazines. The 10-round flush-fit magazine is included, but full-size 17-round and 24-round magazines will also work and extend the grip slightly.
Is the slide cut for direct mounting or do I need a plate?
The slide uses the FN Low-Profile Optics Mounting System with removable adapter plates. You must use the correct plate for your chosen optic. The system is direct-mount once the plate is installed — no adapter shims required.
What holsters fit the FN 509C MRD?
Holsters made for the FN 509 Compact or FN 509C will fit. Brands like Safariland, Tier 1 Concealed, and Vedder offer specific models. The Picatinny rail is MIL-STD-1913 compatible, so light-bearing holsters for the SureFire X300 or Streamlight TLR-1 work with the correct retention profile.
✓ Nationwide delivery (all 50 states)
✓ Ships within 1–2 business days
✓ 30-day returns
✓ Secure checkout
Browse more semi-auto handguns in Semi Auto Handguns or check our complete FN Handguns collection. For compact carry options, see Compact Pistols.
Last updated: April 2026
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