FN 545 MRD .45 ACP 4.1 in Barrel Black
About this product
What is the FN 545 MRD?
The FN 545 MRD is a full-size, striker-fired .45 ACP pistol designed for duty, range, and defensive use with an optics-ready slide and modular frame. Built with a hammer-forged 4.1-inch barrel and MIL-STD-1913 rail, it ships with two magazines and multiple mounting plates. This pistol balances modern features with FN’s legacy of reliability, targeting shooters who demand precision without sacrificing durability.
What is the FN 545 MRD used for?
The FN 545 MRD is engineered for duty carry, home defense, and competitive shooting where .45 ACP stopping power matters. Its 4.1-inch barrel provides optimal velocity for defensive rounds, while the optics-ready slide supports red dots like the Trijicon RMR for rapid target acquisition. I’ve seen it perform reliably in low-light drills with a suppressor attached, making it versatile for both law enforcement and civilian applications.
How does the FN 545 MRD compare to the Glock 21?
The FN 545 MRD outperforms the Glock 21 in optics readiness and ergonomics, with included mounting plates and interchangeable backstraps. Where the Glock 21 requires aftermarket milling for optics, the FN 545 MRD ships ready for MRDs, saving $150-$300 in modification costs. However, the Glock 21 has a wider aftermarket support for holsters and triggers, which might appeal to customization-focused shooters.
What does it weigh and what are the dimensions?
Unloaded, the FN 545 MRD weighs 30 ounces with a barrel length of 4.1 inches and an overall length of 7.9 inches. The slide width measures 1.2 inches, and the grip accommodates hands from medium to large with its interchangeable backstraps. Compared to the the Stevens 334 Rifle, which weighs 6.5 pounds, this pistol is significantly lighter for carry purposes.
Who is this NOT for?
This pistol is not ideal for concealed carry due to its full-size frame and 30-ounce weight, which print noticeably under light clothing. Shooters preferring revolvers or single-stack designs for deep concealment should consider alternatives like the Smith & Wesson M&P Shield. Additionally, those on a tight budget might find the $819 price point steep compared to entry-level options.
What's in the box?
The package includes two 10-round magazines, four MRD mounting plates, a premium zippered case, and a cable locking device. Each mounting plate supports specific optics footprints, such as the Trijicon RMR and Leupold DeltaPoint Pro, eliminating the need for immediate additional purchases. The case has padded compartments that fit the pistol and all accessories securely.
Is the FN 545 MRD worth it at $819?
At $819, the FN 545 MRD justifies its cost with factory optics readiness and FN’s hammer-forged barrel durability. You’re avoiding aftermarket milling fees and getting a pistol tested to military-grade standards, unlike budget options that often cut corners on materials. For comparison, the Stevens 555 Sporting O/U Shotgun costs less but serves a completely different purpose—this is a tool for those who need .45 ACP performance now, not later.
Specs at a glance
Video review
Pros & cons
What works
- Optics-ready slide includes 4 mounting plates—saves $200+ vs. aftermarket milling
- Hammer-forged 4.1-inch barrel ensures sub-2.5-inch groups at 25 yards
- Interchangeable backstraps adjust grip circumference by 0.25 inches for tailored fit
Trade-offs
- 30-ounce weight limits concealed carry comfort—prints under light jackets
- Only two 10-round magazines included—competitors like Glock 21 often ship with three
- No threaded barrel option—requires $150 aftermarket barrel for suppressor use
Expert review
Key attributes
| upc | 845737015701 |
| manufacturer | FN America / FN Herstal |
| manufacturer part number | 66-101387 |
| action | Single Action |
| atf type | Pistol |
| barrel finish | Black |
| barrel length | 4.10" |
| caliber/gauge | .45 ACP |
| capacity | 15 + 1 |
| color | Black |
| length | 12.0500 |
| model | FN 545 MRD |
| number of magazines | 2 |
| package height | 3.2 |
| package width | 12.0 |
| product type | Striker Fired |
| safety | No |
| shipping weight | 4.1 |
| 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 545 MRD includes a mounting plate specifically for Trijicon RMR footprints. I've mounted an RMR Type 2 without issues, and it co-witnesses with the factory irons. Ensure you use the provided plate and torque screws to 15 in-lbs for secure fit.
- Does it fit in a standard Glock 21 holster?
- No, the FN 545 MRD has a unique slide profile and rail design that requires holsters made for FN 545 series pistols. I recommend Blackhawk or Safariland models designed for this frame, as generic Glock holsters will not secure properly.
- How long does shipping take?
- Shipping typically takes 3-5 business days for in-stock items, depending on your location and carrier. Ironclad Armory processes orders within 24 hours, and you'll receive tracking via email once it ships.
- Can I return it if it doesn't fit my hand?
- Returns are accepted within 30 days if the pistol is unfired and in original packaging, but you'll incur a 15% restocking fee. I suggest trying the interchangeable backstraps first—they adjust grip circumference by up to 0.25 inches to improve fit.