The 5.8×21mm is slightly less powerful than similar Western rounds, like the 5.7×28mm and 4.6×30mm. It has a steel-cored 3g (46gr) bullet that has a muzzle velocity of 530m/s (1,700ft/s) and muzzle energy of 420J (310ft·lb) from a submachine gun barrel. The round can penetrate 1.3mm (0.051in) of helmet steel plate, and 50mm (2.0in) of pine wood behind it, out to 100 meters.