FN 5.7mm Five-seveN Pistol Makes Civilian Model Debut
by Larry S. Sterett
Contributing Editor

Originally announced in 1995, after having been under development for some years prior, the Five-seveN pistol was planned for production in 1998. However, it wasn’t until the 2004 Shooting, Hunting and Outdoor Trade (SHOT Show) last February that civilian models were readily exhibited, and the pistol had changed slightly from the original conception.

The test pistol measured 8-5/32 inches long with a barrel length of 4-13/16 inches. (The barrel is rifled with eight grooves having a right-hand twist of one turn in just over 9 inches.) Height of the pistol measured 5-23/32 inches; maximum width measured 1-9/32 inches. Weight of the empty pistol was 24 ounces with the barrel weighing 4 ounces and the 10-round empty magazine weighing 2&Mac186; ounces.

The Five-seveN pistol presents an appearance of being constructed entirely of synthetic materials. It is not. The barrel, springs, trigger, pins, and other stress-bearing parts are steel, plus the entire interior of the slide is steel. There is also a steel guide barrel in the frame beneath the barrel/recoil spring portion.

The Five-seveN pistol has a unique appearance. It appears hammerless, but features an enclosed hammer. The trigger guard has what at first glance is a double bow, with plenty of room for a gloved finger, and the fore portion of the slide is reduced in width relative to the aft portion. The rear of the slide features 11 narrow ridges on each side for grasping, plus a larger pronounced wing on each side. Retracting the slide is much easier than with some more-conventional slide designs. (The original Five-seveN pistols had lower sights, and the breech portion of the slide was slightly concave for grasping. Nor was there a slide stop or manual safety on the left side of the frame, as on the civilian models. In this location was the FN logo.)

Accessory Rail
The lower portion of the frame, forward of the trigger guard, features a rail to accept accessories—a laser, light, etc. The face of the forward guard bow of the original Five-seveN pistols featured a slight concave area, but the current bow has five narrow ridges to reduce forefinger slippage of the off-hand if a two handed-hold is used, and the fore portion of the grip is pebbled to reduce hand slippage. This shooter found the grip of Five-seveN pistol to be extremely comfortable in either hand, as there are slight finger/thumb rests molded into the upper portion.

The Five-seveN pistol is not a locked breech design, but a delayed blow-back design with a reasonably heavy recoil spring. On firing, both the barrel and slide move rearward, but the barrel is under a forward impulse due to the bullet friction.

As the bullet exits the muzzle, the pressure drops and the slide continues rearward to complete the ejection and reloading cycle.

The pistol features a concealed hammer and the trigger is single action with a two-stage pull. (The hammer is cocked by retracting the slide and permitting it to return to battery.) The trigger has a fairly long two-stage pull, with let-off on the test pistol measuring five pounds. The actual trigger is well shaped with 10 small grooves on its face to reduce finger slippage. (There’s a step at the top of the trigger face, just below the frame, and a fleshy finger can get pinched between the frame and the trigger.)

Markings on the Five-seveN include “FN Herstal Belgium” on the left side of the slide, just above the take-down latch on the frame. The FN logo appears on the left and right sides of the grip surface. The right side of the barrel is marked “5.7x28,” along with a proof mark, both visible through the ejection port. The right side of the slide, below the ejection port, is marked “cal. 5.7x28” and the frame to the rear of the safety is marked “FNH USA” above “Fredericksburg, VA.” The serial number appears on a steel plate on the right side of the frame, below the barrel. The FN logo appears on the right grip surface. on the magazines, “5.7x28” appears on the right side and “5” and “10” on the left side near port holes to permit viewing. (The magazines are a black synthetic, with a gray synthetic follower. The magazine floorplate features a slight finger spur.)

20-Round Magazine
Ten-round magazines were standard when the Five-seveN was introduced to the civilian market, but the original magazines had a 20-round capacity, and these are again available. The magazine release is the button type located at the junction of the trigger guard/front strap. It, the safeties, slide release, and take-down button, are gray-color synthetics to contract with the black color of the pistol.

The take-down button, slide release, magazine release, and one manual safety lever are located on the left side of the frame. Each has a molded protecting ramp or projection in front or below it to prevent accidental movement. There is also an automatic disconnect safety when the magazine is removed. If there is a live round in the chamber, the manual safety is “off,” and the magazine is removed, the pistol will not fire; at least the test pistol would not, but it’s just good sense to remove the chambered round when you remove the magazine.

The manual safeties are ambidextrous, with one on each side of the frame, just above the trigger, easily reachable with the trigger finger of either hand. When the safety lever is pointed upward it covers a red-colored dot and is “on.” When the safety lever is moved to the horizontal position the red dot is exposed and the pistol is in the firing mode. Due to the unusual location of the safety lever it may take a bit of getting used to, but the general location of the trigger finger prior to entering the trigger guard makes it a natural to move the safety to the “fire” position with the trigger finger of either hand. It’s simple and can be done as the pistol is being drawn from the holster, if desired.

The sights consist of a 0.142-inch blade front and a 0.115-inch square notch rear, adjustable for windage and elevation. The front blade stands 0.362-inches and features a white dot on the face. A white dot is located on each side of the rear notch, and when the white front is centered between the rear two, you’re “on target.” (The sight radius on the test gun measured 7inches.)

The 5.7x28mm Cartridge
The 5.7x28mm cartridge for this pistol was developed in Belgium in the mid-1980s by FN Herstal for their P90 Personal Defense Weapon (POW). (Currently only the P90 Defense Weapon and the Five-seveN pistol are chambered for this cartridge.) Featuring a bottle-necked rimless, centerfire brass case, the first cartridges were designated the SS190 and featured a boattailed steel jacketed bullet with combination steel/aluminum core. Several versions were available for use in the P90, including ball, tracer, blank, and sub-sonic, and all were said to be Berdan-primed. Listed muzzle velocity was 2,050 feet-per-second (fps).

The current ball load for the US civilian market, loaded to over 2,125 fps, is the SS192. A sample round weighed 95.8 grains, with an empty, unprimed case weighing 58.1 grains, and the bullet having a weight of 27.6 grains. The cartridge length measured 1.589 inches, with the case length measuring 1.131 inches. The boattail bullet measured .850-inch long. (Measurements were taken from a single cartridge and are not average measurements.)

For comparison purposes, a sample ball 5.56 x 45 WCC82 round weighed 176.2 grains, while a .223 Rem-UMC ball round tipped the scales at 176.2 grains. A loaded 5.7mm MMJ round weighed in at 121.4 gains.

The .223-inch diameter SS192 bullet is non-magnetic and features a copper jacket with what appears to be an aluminum core. The SS192 bullet has a 0.300-inch deep hollow nose with an opening of approximately 0.030-inch. The ammunition used in this test was Boxer-primed (small 0.175-inch rifle) with a three-stab crimp and black sealant, and the case head was stamped 5.7x28 and FNB 04.

Range Testing
Following the examination, the Five-seveN pistol was taken for functioning and accuracy testing at the 25-yard range. (FN states the Five-seveN pistol has an effective range of 55 yards and a maximum range of 1,650 yards.) Three-shot groups were fired using the currently available ball load, with a two-hand hold over sandbags. The sight picture was simple, align the three dots horizontally and squeeze off the shots.

Unlike the fixed sights of the original Five-seveN pistol, the civilian model features an adjustable rear sight, but out of the box it is not exactly a target pistol. None of the three-shot groups produced one ragged hole, but all groups fired could be covered by a playing card. (The groups averaged 3-5/16 inches, measured center-to-center, with the smallest group measuring 1-1/8 inches.) At the 25-yard distance the bullets were printing point on, but some yawing was noted. With different bullets it’s possible accuracy could be improved, but the current load is satisfactory for close-in targets.

Recoil of the Five-seveN is mild and seemed less than with some rimfire pistols. The muzzle blast is noticeable, and hearing protection is definitely a requirement.

No feeding or extraction/ejection problems were encountered and ejected cases usually landed some four paces to the right of the firing point. The bottlenecked cartridges feed flawlessly from the staggered column magazine, and when the magazine is empty the slide stays in the retracted position. When a fresh magazine is inserted, the floorplate should be rapped with the heel of the palm to be sure it is securely seated. (If the magazine is not fully seated the pistol cannot be fired.)

The 5.7x28mm cartridge was checked for penetration in compressed saturated wetpack at 25 yards and on 5/32-inch cold-rolled steel plate at 10 yards. Maximum penetration in the wetpack measured 6-1/16 inches with a wound channel approximately 5/16-inch in diameter. The entrance hole was approximately &Mac251;-inch in diameter, and the recovered bullet showed no deformation except for the rifling marks. No penetration was noted on the cold-rolled steel, not even a dimple, just a quarter-inch diameter silver-colored smudge at the point of impact.

Wood Penetration
Additional testing was done on wood at 10 yards. The maximum penetration achieved was 9/16-inch of wafer board backed by 61/2 inches of 2x12-inch board, followed by six inches of non-compressed saturated wetpack. The channels through the boards were little more then .22 caliber while the path through the wetpack expanded and the bullets began to keyhole, coming to rest perpendicular to the path of entry. The bullets used in the 5.7x28 mm SS192 loads will definitely penetration normal wood framed walls at the 10-yard distance.

Pistols chambered for bottlenecked cartridges are not as common as those chambered for straight-walled cases, but they do exist and have for over a century. These include the centerfire 7.63mm Mauser/7.62mm Tokarev, 7.65mm Parabellum, and 8mm Nambu, and more recently the 5.45x18mm, and the rimfire .17 Mach 2. There are others, including the 9x25mm Dillon, the LW7.82Sx24, the .357 Auto-Mag, .357 Grizzly, .357 Peterbilt, and the Portuguese-developed 7.62x24mm, which could be a pistol round.

The FN Five-seveN pistol chambered for the 5.7x28mm cartridge is interesting, both in design, and for the fact it is chambered for a bottlenecked cartridge. It may prove to be a suitable combination for defensive use, as it is definitely lightweight for carrying. The cartridge might even make a handy varmint caliber in a lightweight rifle, such as a mini-Mauser, Ruger M77, or even the M1 Carbine. It could even be a fun gun to try on jackrabbits and prairie dogs, although long shots could be a gamble.


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