FN Five-seveN MRD Pistol Chambered in 5.7x28mm: Full Review

The new FN Five-seveN mini-red-dot-ready handgun is an updated version of the Mk3, still in 5.7x28mm, but with a redesigned barrel and a renown adapter plate and hardware kit. Here's a full review.

November 22, 2022 By Guns & Ammo Staff

It’s about time. Developed as a complement to the FN P90 personal defense weapon (PDW), the “Five-seveN” pistol, also chambered for the 5.7x28mm cartridge, was first seen in 1998. The Five-seveN featured a higher-than-normal capacity of 20 rounds, which was impressive when one considers that the magazine for the standard-issue M9 9mm only carried 15 rounds. This design approach echoed the progressive theme of the select-fire P90 and semiautomatic PS90, which operated from 50-round magazines, and the feature set continued. The Five-seveN featured a lightweight polymer frame and magazine, ambidextrous controls, low recoil and the ability to penetrate body armor when used with certain cartridge types.

FN Five-seveN MRD Pistol Recoil Spring — The Five-seveN wears the recoil spring around its 4.8-inch barrel. The pistol features delayed blowback operation, so the barrel only moves slightly rearward with the slide before it stops in place. (Guns & Ammo photo)

In 2004, the first samples appeared in the U.S. and were reviewed by Guns & Ammo. However, misleading news of the armor-piercing ammunition forced FN to restrict sales to military and law enforcement, while demonstrating that non-armor-piercing sporting loads — the SS192 and SS196 — would not penetrate Kevlar vests. That same year, the Five-seveN USG model updated the pistol with a square-shaped trigger guard, fine molded checkering and a reversible magazine release. From 2005 to 2010, several attempts by Congressional representatives were made to specifically ban the pistol and 5.7mm ammunition without success. During the same period, the list of military and law enforcement users grew to more than 300, including the U.S. Secret Service. The Five-seveN MK2 followed in 2013, which replaced the USG model and introduced serrations at the front of the slide, black controls and improved sights, to name a few details.

FN Five-seveN MRD Pistol Sights — Having a standard 3-dot layout, the suppressor-height sights are fixed at the front and fully adjustable at the rear. When a red dot is mounted, most available optics will co-witness with the sights. (Guns & Ammo photo)

The commercial demand for Five-seveN pistols was tempered by its near $1,500 price point and a limited variety and the availability of ammunition. (The company held exclusive contracts to produce ammunition under the FN brand until recently.) Then, in December 2019, Sturm, Ruger & Co. announced its lower-priced Ruger-5.7 ($869) in the wake of expired patents. [Palmetto State Armory (PSA) also followed with its 5.7 Rock for $500.] Suddenly, combined with AR-style rifles and pistols such as the CMMG Banshee ($1,750) and Diamondback DBX57 ($1,352), public interest in firearms chambering the 5.7x28mm cartridge spiked.

FN was ready to respond in 2022 with the new Mk3, which is commercially known as the Five-seveN MRD.

FN Five-seveN MRD Pistol Slide Serrations — The slide serrations at the front and rear are new, and there are subtle “wings” at the back that support users racking the slide. Note: The rear sight is independent of the MRD footprint and coverplate. (Guns & Ammo photo)

The Updates

The Five-seveN MRD is still chambered in 5.7x28mm, but every other characteristic seems to have received an update. Out of the box, the slide looks almost normal. However, the 4.8-inch hammer-forged barrel now wears a target crown. At the rear, a polymer plate conceals the optic-ready feature, just in front of the rear sight. The “MRD” in the name indicates that these pistols have a factory-milled, low-profile optic cut for “mini red dot” sights. Not only is it low, FN’s MRD adapter plate and hardware kit remains the most complete kit included with any pistol Guns & Ammo has ever tested. (These comprehensive MRD kits are provided with other FN handguns, too.) Consult the Owner’s Manual and you’ll find a generous list of compatible optics with a clear reference to the needed mounting plate and screws.

FN Five-seveN MRD Pistol Adapter-Plate and Screw Kit — FN provides the industry’s most complete adapter-plate and screw kit, along with a comprehensive reference chart in the owner’s manual to mount most optics to its MRD models. (Guns & Ammo photo)

G&A’s staff successfully tested several common red-dot sights including the Burris Fastfire III, Leupold DeltaPoint Pro, Holosun 507, Trijicon RMR and Vortex Venom. When mounted, the optic sits in front of and below the suppressor-height, adjustable iron sights, which means that most optics will co-witness or support the use of the standard sights as a backup should the optic fail. As standalone sights, the front appears as tall as a shark fin, but if the barrel is given a suppressor, these three-dot sights support aimed and accurate fire. The dots are not tritium-powered night sights; instead, they were created with photo-luminescent paint that glows in low-light conditions. (This is not uncommon on pistols manufactured and imported from Europe.) Unfortunately, the glow isn’t that useful in the dark if they are not first charged by a flashlight or other light source.

Controls are still low-profile and easy to reach on the Five-seveN. The magazine button was enlarged, serrated and reshaped, but the slide-lock lever still only favors right-handed shooters. (Guns & Ammo photo)

Flat Shooting

A benefit to attaching a red-dot sight to the Five-seveN is that it improves the perceived accuracy potential of almost all shooters out to 100 yards. (The accuracy potential is always there, but using a red dot eliminates the need to align the front and rear sight over the target plane.) Without an optic, the Five-seveN is easily a 21/2-inch-accurate pistol, but it was possible to produce 1½-inch five-shot groups from 25 yards with an optic. Given that the Five-seveN produces little felt recoil and muzzle flip, rapid fire using a red dot felt more like shooting an air gun than a centerfire.

Operationally, the Five-seveN is unchanged. It remains a delayed blowback-operated pistol, which proved extremely reliable, but the slide and frame have been strengthened within. It isn’t striker-fired, though, which means that it operates using an internal single-action-only (SAO) hammer. As a result, the trigger pull feels glass-rod-like and less spongy than the typical striker-fired pistol. However, the pull weight on G&A’s two test pistols averaged more than 8 pounds. The short take-up collects some of that pull weight, but the trigger feels “all at once.” It is predictable, and the trigger profile is the only reason such accuracy can be achieved from a pistol with a heavy pull. (Conversely, FN advertises 6-pound trigger averages.) A credit to the SAO design, reset was short, which allowed for fast follow-up shots. It takes seconds to fire through either of the 20-round magazines with less dispersion on target than you’d expect.

FN Five-seveN MRD Pistol Stippling Pattern — A standard stippling pattern is present on either side of the grip, while the frontstrap is aggressively serrated with a finger contour at the top. The narrowing and new contoured design is a significant enhancement versus the original Five-seveN models. The magazine baseplate blends well with the frame and supports a high and consistent grip. (Guns & Ammo photo)

Under Control

The slide-serration grooves are new for the Five-seveN MRD, and the extended cocking ridges at the rear of the slide are available for those who like to rack the slide like pulling a slingshot. Overall, the control levers and switches were enhanced, along with the reduced profile, contoured finger placement, and textured surfaces of the grip. The stipple-type texture on the grip’s sides and extensively serrated frontstrap modernize the feel of the Five-seveN and provide better, more comfortable control than previous generations.

The enhanced ergonomics also translate to easier reach of the controls. Still, the low-profile, index-finger-actuated, ambidextrous safety selector is in the same familiar location, above the trigger. It seems unusual at first to swipe the safety up and down, but it does keep the finger off the trigger when manipulating this control.

While the magazine release button was enlarged, serrated and reshaped for easier reach, it still must be removed and reinstalled if you want it set up for the left hand. Inside the grip, the Five-seveN MRD accepts the new Mk3 20-round magazines, which are designed for use with the reversible magazine release. (Spares and 10 rounders are available at fnestore.com, $45).

The only other controls on the Five-seveN are the fenced-in slide-lock/-release lever, which is easily manipulated with the thumb, and the sliding disassembly button above the front of the triggerguard. Field stripping may seem unusual to those who skip reading the manual because the recoil spring surrounds the barrel. With the slide off, press the barrel forward and lift it out of the slide. While examining the slide, you’ll notice that the steel slide assembly is actually within a polymer shell. We’re speculating, but this must reduce slide mass for reliable operation, save manufacturing costs and allow future aesthetic updates without having to re-engineer metal workings.

FN Five-seveN MRD Pistol 20-Round Mk3 Magazines — The new 20-round Mk3 magazines are designed for use with the reversible mag release. The compact size of the 5.7mm round, and the full-size nature of the Five-seveN, add up to equal its large capacity. Of course, 10-round magazines are available for low-capacity jurisdictions. $45 (Guns & Ammo photo)

At The Range

G&A Editor-in-Chief Eric Poole and Field Editor Keith Wood teamed up to test and evaluate the Five-seveN MRD. Poole has owned each variation of the Five-seveN since its first gun-media appearance in 2004, and both have evaluated the competition. If you ever had a need or desire for a pistol chambered in 5.7mm, and you were not put off by the higher price of the FN, this is the version you would want. In total, more than 500 rounds of FN’s lead-free 27-grain SS195 were fired through each sample without incident or malfunction. The Five-seveN remains a flat shooter, but neither could find a way to properly underscore just how controllable, reliable and accurate these pistols were.

Much of the function test was done during wet weather against steel targets and cardboard silhouettes scattered between 10 to 50 yards. From an unsupported standing position, Poole produced a 20-shot group using a red-dot-equipped Five-seveN that measured less than nearly 1¾ inches at 15 yards before pressing on. When it was time to test accuracy on paper at 25 yards, a sort-of competition ensued. These guns proved to be loads of fun until the ammo ran out.

FN Five-seveN MRD Pistol Proved Incredibly Accurate — Testing handguns with a large number of rounds can get tedious depending on the caliber, size of the frame and trigger. With the Five-seveN MRD, G&A staff spent hours at the range and kept coming back to shoot it more. It proved incredibly accurate. (Guns & Ammo photo)

Some question the efficacy of the 5.7x28mm cartridge for personal defense, while others argue that the added capacity makes up for any compromises made in manufacturing the commercial sporting ammunition. Making 5.7mm ammunition is still a challenge due to the proprietary adhesive used to ensure ideal neck tension between the bullet and case mouth. Therefore, almost no other company attempts to load or reload spent cases despite these new guns. FN and Federal are still the primary sources for commercial ammunition, but we expect to see Speer’s 40-grain Gold Dot load soon. Unavailable at the time of this writing, the new Gold Dot load is projected to cost $87 for 50 rounds. That may limit the Five-seveN’s success as a self-defense pistol, but a Gold Dot round should eliminate core-jacket separation in tissue and make the cartridge viable for personal protection.

In June 2022, FN Herstal and Fiocchi announced a new agreement to manufacture and supply 5.7x28mm ammunition to the U.S. market. If this occurs, we may see the demand and pricing ease. With current interest and enthusiasm for these new firearms, we have our fingers crossed.

The Five-seveN MRD is available in matte black or the FN Flat Dark Earth (FDE). Shipped in a cardboard box, both include an excellent, FN-embroidered nylon pistol case with sewn-in magazine pouches and a zippered storage compartment. Inside you’ll find the two magazines and MRD optic-mounting hardware. FN has provided every reason to justify the purchase of its latest Five-seveN, but at the current MSRP it will likely remain an impulse buy. We say, “Go ahead, you know you want one.”

FN Five-seveN MRD Specifications

Type: Delayed blowback operated, hammer fired, single-action only (SAO), semiautomatic
Cartridge: 5.7x28mm
Capacity: 10 rds. or 20 rds.
Barrel: 4.8 in., cold hammer forged
Overall Length: 8.2 in.
Height: 5.8 in.
Width: 1.31 in.
Weight: 1 lbs., 9.2 oz.
Grip: Textured; stippled, serrated
Finish: Black or FDE
Sights: Three-dot, adj.; MRD (optic ready)
Trigger: 8 lbs., 6 oz. (tested)
Safety: Manual selector lever, internal disconnector
MSRP: $1,449
Manufacturer: FN America, 703-288-3500, fnamerica.com