Where It All Began
The story of the 5.7 gun starts in the 1970s, when Belgian engineers at FN Herstal—home of the iconic FAL rifle—began experimenting with a new kind of cartridge. The Cold War had made small arms obsolete in one sense: larger rounds like the 7.62×51mm NATO were overkill for urban combat, but lighter calibers lacked stopping power. Enter the 5.7×28mm, a project led by engineer René Brunet, who wanted a round that could penetrate body armor while remaining manageable in automatic weapons. The result was a hybrid: a small case filled with a heavy, high-velocity projectile designed to tumble upon impact, maximizing tissue damage. The prototype emerged in 1982, but skepticism ran deep. The U.S. military had rejected similar concepts in the past, and the 5.7 gun’s plastic-tipped SS190 bullet—later replaced by the SS193—was seen as gimmicky. Yet Belgium’s Special Forces Group (GRI) adopted it in 1990, using it in the FN P90, a weapon that would later become one of the most recognizable firearms of the 21st century. The 5.7 gun’s first real test came in the early 1990s during peacekeeping missions in the Balkans, where its suppressed effectiveness in close quarters gave it an edge over louder, heavier calibers.The Early Signs
By 1993, the 5.7 gun had crossed the Atlantic—not as a military round, but as a civilian curiosity. FN introduced the Five-seven pistol, a polymer-framed, striker-fired handgun chambered in 5.7×28mm. It wasn’t the first pistol in the caliber, but it was the most accessible. Law enforcement agencies in the U.S. and Europe began experimenting with it, drawn to its suppressed potential and the ability to engage targets at ranges where handguns typically faltered. The round’s 1,600-foot-per-second muzzle velocity (with the SS193) allowed it to outperform .40 S&W and 9mm in ballistic gel tests, despite its smaller size. Yet the civilian market remained lukewarm. Ammunition was scarce, and the pistol’s $1,000-plus price tag limited its appeal. Critics argued that the 5.7 gun was a solution in search of a problem—why carry a niche caliber when 9mm was tried and true? But the real turning point wasn’t sales figures; it was how the military used it. In the late 1990s, U.S. Special Operations Command (SOCOM) quietly evaluated the P90, and by the early 2000s, the 5.7 gun had infiltrated elite units, including the Delta Force and SEAL Teams, where its suppressed fire and armor-piercing potential made it ideal for hostage rescue and urban operations.The Turning Point
The shift came in 2003, when the U.S. military’s Joint Special Operations Command (JSOC) officially adopted the P90 for certain missions. The 5.7 gun was no longer just a European curiosity—it was a tactical game-changer. Its ability to fire subsonically (with the SS193) meant operators could engage targets without giving away their position, a critical advantage in environments where noise discipline was paramount. Meanwhile, FN had begun marketing the Five-seven pistol to U.S. law enforcement, positioning it as the "suppressed pistol" for SWAT teams. The backlash wasn’t long in coming. Gun control advocates seized on the 5.7 gun’s potential for civilian misuse, particularly its ability to be fired suppressed. In 2005, a New York Times article framed the cartridge as a "stealth weapon," sparking debates about whether it belonged outside military and police use. The NRA, however, defended it as a legitimate self-defense tool, citing its superior ballistics over traditional handgun rounds. The controversy only fueled its mystique.
The Build-Up, Year by Year
| Period | Key Developments |
|---|---|
| 1982–1990 | FN Herstal develops the 5.7×28mm; Belgian GRI adopts it for the P90. First real-world testing in Balkans peacekeeping missions. |
| 1993–1999 | Civilian Five-seven pistol introduced; limited law enforcement adoption. Ammunition supply remains constrained. |
| 2000–2005 | JSOC adopts P90; 5.7 gun gains traction in U.S. special operations. Media scrutiny grows over civilian suppressed fire concerns. |
| 2006–2012 | FN expands 5.7 gun platform with the F2000 rifle and SR9 submachine gun. Civilian market remains niche but loyal. |
| 2013–Present | U.S. manufacturers like Magpul and CMMG introduce 5.7 gun rifles. Ammunition production increases but stays expensive. Debates over civilian suppressed use persist. |
Lessons From the Journey
- Size isn’t a limitation. The 5.7 gun proved that smaller calibers could deliver performance once reserved for larger rounds.
- Suppressed fire changes tactics. Its adoption in special operations forced a rethink of urban combat strategies.
- Civilian adoption is slow but steady. The market remains small, but enthusiasts value its unique advantages.
- Regulation follows innovation. The 5.7 gun’s suppressed potential sparked legal debates that still influence gun policy.
- Legacy outlasts hype. While not a mainstream caliber, it remains a benchmark for future small-caliber development.
Where Things Stand Today
The 5.7 gun is no longer a novelty—it’s a specialized tool. In military and law enforcement circles, it’s a proven asset, used by units from British SAS to Israeli special forces. The P90 remains in service, and newer platforms like the FN F2000 rifle and CMMG M45 keep the caliber relevant. Meanwhile, civilian adoption has expanded, though slowly. Companies like Magpul and Kel-Tec have introduced 5.7 gun rifles, and suppressors for the caliber are more accessible than ever. Yet challenges remain. Ammunition costs three to five times more than 9mm, and production bottlenecks persist. The civilian market is still a fraction of what it could be, held back by price and limited training resources. But the 5.7 gun’s influence is undeniable—it forced the industry to reconsider what a "handgun" or "rifle" could be, and its legacy lives on in newer rounds like the 6.8mm Remington and 6.5mm Grendel, which borrowed its high-velocity philosophy.
Conclusion
The 5.7 gun’s story is one of underestimation and persistence. When it debuted, skeptics dismissed it as a fad—too small, too niche, too different. Yet it endured because it solved real problems: suppressed fire, armor penetration, and precision at extended ranges. Its journey from Belgian special forces to U.S. SWAT teams to civilian shooters’ wish lists is a testament to how innovation often outpaces convention. Today, the 5.7 gun occupies a unique space—neither mainstream nor obsolete. It’s a reminder that in the world of firearms, the most interesting developments aren’t always the loudest.Comprehensive FAQs
Q: Is the 5.7 gun legal for civilians in the U.S.?
The 5.7×28mm cartridge is legal, but suppressors for it require ATF approval under the National Firearms Act (NFA). Some states have additional restrictions on suppressed firearms.
Q: How does the 5.7 gun compare to 9mm?
The 5.7 gun offers higher muzzle velocity (1,600+ fps vs. 9mm’s ~1,200 fps) and better penetration, but 9mm has more recoil control and cheaper ammunition. For suppressed use, 5.7×28mm is superior.
Q: Why is 5.7 gun ammo so expensive?
Low production volume and specialized components (like armor-piercing SS193 bullets) drive up costs. Figures around $0.50–$1.00 per round are common, compared to pennies for 9mm.
Q: What’s the most popular 5.7 gun firearm?
The FN P90 remains the most widely used, followed by the Five-seven pistol and FN F2000 rifle. Civilian rifles like the CMMG M45 are gaining traction.
Q: Can the 5.7 gun penetrate body armor?
Yes—with the SS193 bullet, it can penetrate Level IIIA soft armor (NIJ standard) at close ranges, though effectiveness drops beyond 50 yards.
Q: Will the 5.7 gun ever become mainstream?
Unlikely in its current form, but its influence on high-velocity small calibers ensures its principles will shape future designs.
