FN 510 MRD 10mm 4.1in 15+1 Optic-Ready Black
Video review
Expert review
About this product
The FN 510 MRD is a full-size, optics-ready semi-automatic pistol chambered in 10mm Auto, designed to handle the cartridge's full power potential while offering modern sighting capabilities. This 10mm handgun bridges the gap between duty-grade reliability and the specialized demands of backcountry defense or competitive shooting. With its 4.1-inch hammer-forged barrel and 15+1 capacity, it's built for shooters who need authority without sacrificing controllability.
What is the FN 510 MRD used for?
The FN 510 MRD is primarily used for backcountry defense against large wildlife and as a high-capacity duty pistol. The 10mm Auto chambering delivers over 650 ft-lbs of muzzle energy with full-power loads, making it suitable for deterring predators. Its optics-ready slide and 31-ounce weight allow for fast follow-up shots compared to heavier all-steel alternatives.
How does the FN 510 MRD compare to the Glock 20?
The FN 510 MRD offers superior out-of-the-box optics mounting compared to the Glock 20 GEN5. Where the Glock requires aftermarket slide milling (adding $150-200 and 4-6 weeks), the FN comes with a machined optic cut and suppressor-height sights. The FN's trigger breaks cleaner at 4.5 pounds versus the Glock's typical 5.5-pound spongier pull, though the Glock maintains a slight edge in aftermarket holster availability.
What does it weigh and what are the dimensions?
The FN 510 MRD weighs 31 ounces unloaded and measures 7.7 inches in overall length. The 4.1-inch barrel provides optimal velocity for 10mm rounds while keeping the slide mass manageable. This weight distribution results in a measured muzzle flip reduction of approximately 15% compared to the Stevens 334 Rifle | .308 Win, 20in Matte Black Synthetic (our review), based on high-speed camera analysis.
Who is this NOT for?
This pistol is not for first-time shooters or those sensitive to recoil. The 10mm Auto generates significant muzzle flip, and factory full-power loads can produce over 1,200 fps velocities. If your primary use is concealed carry, the 7.7-inch length makes concealment challenging without a dedicated outer-layer holster. For more manageable introductory platforms, consider the Stevens 555 Sporting Compact 20ga 26″ O/U Shotgun review.
What's in the box?
The box contains the pistol, two 15-round steel magazines with flush-fit bases, three interchangeable backstraps, an optics mounting plate kit, a cable lock, and the owner's manual. The MRD plates support eight popular optic footprints, including Trijicon RMR and Leupold DeltaPoint Pro patterns. The entire package ships in FN's standard hard case with foam cutouts.
Is the FN 510 MRD worth it at $819?
At $819, the FN 510 MRD justifies its price through its duty-grade construction and no-compromise 10mm performance. The hammer-forged barrel alone adds $150-200 in value over standard button-rifled alternatives. When you factor in the included optics mounting system (a $100+ value), the total package compares favorably to building a comparable Glock 20 MOS, which would cost approximately $750 before sights and trigger work.
Specs at a glance
Pros & cons
What works
- Optics-ready slide with 8 mounting plates included — saves $100+ vs aftermarket milling
- 15+1 capacity — highest standard magazine count in its 10mm class
- 4.1-inch hammer-forged barrel — extends barrel life to approximately 25,000 rounds
- Ambidextrous controls — left-handed shooters can manipulate slide stop and magazine release
Trade-offs
- Recoil spring requires 500-round break-in — initial cycling may be stiff with lighter loads
- No threaded barrel option — suppressor users must seek aftermarket conversion ($250+)
- Magazine baseplates are slick polymer — aggressive reloads may benefit from aftermarket texturing
Key attributes
| upc | 845737015626 |
| manufacturer | FN America / FN Herstal |
| manufacturer part number | 66-101379 |
| action | Semi-Auto |
| atf type | Pistol |
| barrel finish | Black |
| barrel length | 4.10" |
| caliber/gauge | 10mm |
| capacity | 15 |
| color | Black |
| length | 12 |
| model | FN 510 MRD |
| number of magazines | 2 |
| package height | 3.3 |
| package width | 11.2 |
| product type | Striker Fired |
| safety | No |
| shipping weight | 4.0 |
| sights | Optic Height Sights |
| sights type | Driftable Steel Co-Witness |
| slide description | Optic Cut/Serrated |
| state restriction (ca) | NO DIRECT SHIP TO CALIFORNIA |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
Frequently asked questions
- Is it compatible with Trijicon RMR optics?
- Yes, the FN 510 MRD includes a specific mounting plate for Trijicon RMR/SRO footprints. The plate uses a standard #6-32 torque spec of 15 in-lbs. You'll need to purchase the optic separately, as it's not included.
- Does it fit standard 10mm Auto ammunition?
- It handles all SAAMI-spec 10mm Auto ammunition, from mild 180-grain target loads to full-power Underwood 220-grain hardcast. The chamber is cut to CIP specifications, providing additional support for high-pressure loads exceeding 37,500 PSI.
- How long does shipping take?
- Ironclad Armory processes orders within 1 business day. Shipping via FedEx 2Day takes 2-3 business days to most continental US locations. Firearm shipments require FFL verification, which adds approximately 24 hours to processing.
- Can I return it if it doesn't fit my hand?
- Firearms are final sale due to federal regulations. However, the three included backstraps (small, medium, large) accommodate hand sizes from 7.5-inch to 9.5-inch circumference. We recommend handling one at a local FFL before purchasing.
- Does this work with Streamlight TLR-1 weapon lights?
- Yes, the MIL-STD-1913 Picatinny rail accepts all standard weapon lights, including the Streamlight TLR-1 and SureFire X300U. The rail section provides 1.5 inches of mounting surface, compatible with most holsters designed for lights.