The 6.5×25mm CBJ is a firearm cartridge designed by CBJ Tech AB, a Swedish weapon development company based in Kungsbacka, for its CBJ-MS submachine gun/personal defence weapon.
Named after CBJ Tech AB's founder and president Carl Bertil Johansson,[3] the 6.5×25mm CBJ has the same functional dimensions as the 9×19mm Parabellum and was designed to produce the same recoil and pressures to allow most 9 mm caliber weapons to be converted to 6.5×25mm CBJ with a simple barrel change.
The primary loading of the standard ball round fires a saboted 2 g (31 gr), 4 mm (0.16 in) diameter tungsten kinetic penetrator, weighing a total of 2.5 g (39 gr) with the sabot.
[4][5] From a 300 mm (12 in) barrel, the tungsten saboted round has the same trajectory as a 5.56 NATO from an M4 carbine and a velocity of 578 m/s (1,900 ft/s) at 300 m (328 yd), which will penetrate CRISAT armor.
Military rounds include a "spoon-tip" loading that increases the chance of the bullet to cavitate on impact and a cheap training version with a different core material.