FN Five-seveN: An extraordinary pistol chambered in unusual caliber

FN Five-seveN is a great semi-automatic pistol developed by FN Herstal Belgium in parallel with the P90 and conjunction with a 5.7×28 mm cartridge. The

Eric Sof

FN Five-seveN chambered in 5.7x28 mm
FN Five-seveN chambered in 5.7x28 mm (Photo: XY)

FN Five-seveN is a great semi-automatic pistol developed by FN Herstal Belgium in parallel with the P90 and conjunction with a 5.7×28 mm cartridge. The pistol’s name, Five-seveN, refers to the bullet diameter. P90 and Five-seveN were developed for the NATO Personal Defense Weapon (PDW) requirement.


The P90 was designed around a new high-velocity armor-piercing 5.7 mm cartridge that could penetrate body armor and was effective to about as much range as you need. The weapon was designed to give military forces a credible option for a small, punchy, practical weapon to arm everyone outside the infantry. That’s a big market; the infantry only makes up a small percentage of a modern nation’s military strength. Similar thoughts were with the FN Five-seveN.

FN initially restricted sales of the Five-seven to military and law enforcement customers, but since 2004, the pistol has also become available to civilians alongside the civilian version P90, designated as PS90. The Five-seven is currently in service with military and police forces in over 40 nations, including Canada, France, Greece, India, Poland, Spain, and the United States. In the United States, the Five-seven is used by numerous law enforcement agencies, including the US Secret Service CAT.

A member of U.S. Secret Service armed with FN P90 submachine gun
A member of the US Secret Service armed with an FN P90 submachine gun (Photo: XY)

If you’re a military operator who wants to ditch your ineffective old 9 mm weapons and climb on board the 5.7 mm train, then the P90/Five-seven combo makes sense. You’re not the target market if you’re a civilian, so you might find the whole thing a bit perplexing. But FN knows what they’re doing and aren’t prone to “stunts.”


The FN P90 was introduced in 1990, while the Five-seveN was introduced in 1998 as the pistol that addressed the problem of what to arm non-frontline military personnel with. Not only were they made in conjunction, but the P90 and Five-seveN shared many design features, including:

  • lightweight polymer-based
  • a relatively large magazine capacity
  • ambidextrous controls
  • low recoil
  • ability to penetrate body armor when using certain cartridge types

FN Five-seveN has a traditional design with delayed blowback operation. It features a double-action trigger, allowing it to be carried with a loaded chamber. There is a version with a single-action-only trigger. There is an ambidextrous safety switch mounted above the trigger. It also has internal firing pin safety. Early models of the FN Five-seveN had firing pin safety only with no manual safeties.

The pistol consists of four main parts that the user can easily dismantle. The weapon is fed from a double-stack magazine that holds 20 rounds. The magazine release button is ambidextrous, which can be reversed from the left side of the grip to the right.

Illuminated fixed sights at Five-seven USG pistol day/night view
Illuminated fixed sights at Five-seven USG pistol day/night view (Photo: Wiki Commons)

FN Five-seveN standard version features simple iron sights designed for the range of effective fire up to 100 meters. The grip can be fitted with backstraps of various sizes. So the pistol can be tailored to fit well in almost every hand. There is an accessory rail under the barrel. Users can use it to mount tactical flashlights or laser pointers. This pistol is compatible with a sound suppressor. Once fitted with a sound suppressor, it has to use special subsonic bullets (decreased speed).


As was mentioned, the whole Five-seveN project was around the high-velocity 5.7×28 mm SS190 cartridge. FN Herstal developed it in the late 1980s, and it resembles a scaled-down standard NATO 5.56×45 mm Remington round. It is a potent cartridge, larger than a traditional pistol and submachine gun ammunition but smaller than assault rifle ammunition.

The main advantage of this cartridge is its high velocity. This packs a 5.7 mm round with impressive penetration potential making it effective against armor vests, helmets, and ballistic glass. According to the FN, the Five-seveN penetrates a standard CRISAT (kevlar + titanium) vest at 100 meters and a PAGST vest at 300 meters.

From left to right: SS195LF hollow point, SS196SR V-Max, and SS197SR V-Max
From left to right: SS195LF hollow point, SS196SR V-Max, and SS197SR V-Max (Photo: FN)

Various rounds are available, including standard, tracer, and round with subsonic bullet speed. The Five Seven is the only handgun chambered for this unique cartridge. However, the cartridge is the only novelty of this pistol.

Pros and cons for 5.7 mm cartridge


Low recoil, high magazine capacity, accurate and reliable at further distances than most handguns without expert training, and light for a full-sized gun.


freaking expensive gun and rounds. The cartridge is huge, so if you have small hands, it won’t be ergonomically comfortable to hold and shoot. Freaking loud, it’s a small rifle round, huge muzzle flash which in darkness can be blinding. Less availability of other guns that shoot that round, so not as easy to get a collection if you want one.


And the last thing I forgot to mention is the price of the Five-seveN. It’s costly and not widely available. It also shoots a specialized and expensive round that you won’t find on the shelf at every local gun shop.

Technical specifications

Country of origin:Belgium
Manufacturer:Fabrique Nationale Herstal (FN Herstal)
Caliber:5.7×28 mm
Weight (empty):618 g
Weight (loaded):744 g
Length:208 mm
Barrel length:122 mm
Muzzle velocity:650 m/s
Magazine capacity:20 rounds
Sighting range:50 m
Range of effective fire:up to 100 m

Eric Sof

Eric Sof holds a master's degree in Political Science, specializing in International Peacekeeping Studies. He has over a decade of experience as a former member of an elite counterterrorism unit. Additionally, he is a firearms instructor and currently serves as a member of the SWAT unit.

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4 thoughts on “FN Five-seveN: An extraordinary pistol chambered in unusual caliber”

  1. Just went and handled the SMITH& WESSON 5.7×28 at the gun store and I am on the list to get one next pay day. I have fired the FN and it is impressive, but expensive yet I could hit a quarter size target at 25 yards!

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