Unleashing the Future: 5.7x28mm from FN Herstal—NATO’s Game-Changing Round for Firearms

Based in Belgium, FN Herstal, a preeminent creator and producer of small caliber firearms and ammunition, along with integrated weapon systems, is excited to declare that the FN®-engineered 5.7x28mm caliber has recently been recognized as a NATO caliber under the NATO STANAG 4509 (standardization agreement).

FN Herstal, the pioneering creator of the 5.7x28mm caliber

The design of the 5.7×28mm cartridge began at FN Herstal in the late 1980s, coinciding with the adoption of body armor as standard military gear, necessitating a more suitable and effective cartridge for modern combat scenarios.

At the same time, FN Herstal was developing the FN P90® Personal Defense Weapon (PDW) and later the FN Five-seveN® pistol, both of which utilize 5.7x28mm ammunition and are actively employed by numerous military and law enforcement agencies worldwide.

STANAG 4509

In its ongoing commitment to enhance the compatibility of all small caliber ammunition utilized by allied military forces, NATO has recently completed the standardization of the FN®-engineered 5.7x28mm caliber by issuing the standardization agreement (STANAG) 4509.

The 5.7x28mm caliber is now included in the Multi-Caliber Manual of Proof and Inspection (AEP-97) and joins the standardized NATO small caliber ammunition inventory, which also includes 9x19mm NATO, 5.56x45mm NATO, 7.62x51mm NATO, and 12.7x99mm NATO (commonly referred to as the .50 caliber). As a standardized NATO caliber, the 5.7x28mm offers military forces assurance of interoperability between ammunition from various manufacturers and operational effectiveness in weapons chambered for this caliber.

This standardization introduces a fresh option within the Handgun and Submachine gun segments, fulfilling the criteria set forth by NATO Army Armament Group’s LCGDSS (Land Combat Group Dismounted Soldier System), as outlined in the «NEW NATO INFANTRY SMALL ARMS POST 2025» document*. Sponsored by the Belgian Army, the FN® P90 submachine gun and the FN Five-seveN® pistol are set to become the inaugural NATO Nominated Weapons in the 5.7x28mm caliber.

Following the standardization of FN®-designed 5.56x45mm and 7.62x51mm calibers by NATO in 1957 and 1981 respectively, this latest NATO certification reaffirms FN Herstal’s preeminence as a designer and producer of small caliber weapon-ammunition systems. It also solidifies the Belgian firm’s commitment to equipping contemporary military and security forces worldwide with top-tier, high-performance small caliber ammunition innovations and designs.