6.5×25mm

The 6.5x25mm CBJ is a pistol cartridge designed for the CBJ-MS personal defence weapon. Capable of use in rebarreled 9 mm Parabellum firearms, the primary loading of the round fires a sabotted 4 mm tungsten sub-projectile.

The 6.5x25mm CBJ has the same functional dimensions as the 9x19 Parabellum and was designed to produce the same recoil and pressures to allow most 9mm weapons to be converted to 6.5x25mm CBJ with a simple barrel change.

Because the 6.5x25mm CBJ has the same overall dimensions as the 9x19 Parabellum, it can be used in 9 mm magazines. The standard ball round fires a saboted tungsten 2 g 4.0 mm diameter sub-projectile. It has a muzzle velocity of 730 m/s from a 120 mm barrel with a muzzle energy of 533 J. From a 300 mm barrel, it has a muzzle velocity of 900 m/s with a muzzle energy of 810 J, and has good armor penetration out to 400 meters. The standard saboted tungsten ball round can pierce 9 mm of armor plate and leave a 6 mm diameter entry hole when fired from a 300 mm length barrel. By comparison, 5.56 NATO and 7.62 NATO rounds cause little or no penetration to armor of that thickness.