The 5.7x28mm FN cartridge, developed by FN Herstal in the late 1980s, is a small-caliber, high-velocity round designed for personal defense weapons (PDWs) and pistols. It was originally created to replace the 9x19mm Parabellum cartridge for NATO forces, offering better range, accuracy, and armor-piercing capabilities.
The 5.7x28mm is characterized by a bottlenecked case design, which allows it to propel lighter bullets at higher velocities than traditional handgun cartridges. Typical bullet weights range from 23 to 40 grains, with velocities around 2,350 feet per second for a 23-grain projectile.
The cartridge is used in firearms such as the FN P90 PDW and the FN Five-seveN pistol. Its flat trajectory, low recoil, and ability to penetrate body armor make it suitable for military, law enforcement, and civilian self-defense applications. The 5.7x28mm FN has also gained popularity among sport shooters and enthusiasts for its unique performance characteristics.
Despite its advantages, it is often a topic of debate regarding its stopping power compared to larger calibers. Nonetheless, its specialized role and high performance continue to make it a noteworthy cartridge in specific defensive and tactical scenarios.