The 5.7x28mm FN P90 was developed in the late 1980s by FN (Belgium) for its new P90 personal defense gun. This cartridge is intended to replace the 9x19mm Parabellum pistol cartridge. Claimed ballistic performance is much superior to the 9mm cartridge.
The 5.7x28mm cartridge is similar to the 221 Fireball cartridge, but are not interchangeable. Originally a sharply pointed Ball bullet weighing only 23 grains is used, as intended range is limited. Military load will push this 23 grs bullet to 2790 fps.
This text is based on information from “Cartridges of the
World”, Hodgdon reloading manual, the cartridge designer and/or