5.7 x .28 FN

The FN 5.7×28mm is a small-caliber, high-velocity, smokeless powder, rebated rim, bottlenecked centerfire cartridge designed for handgun and personal defense weapon (PDW) uses manufactured by FN Herstal. It is similar in length to the .22 WMR (5.7×27mm) and to some degree similar also to the .22 Hornet or .22 K-Hornet. Unlike many new cartridges, it has no parent case; the complete package was developed from scratch by FN.