The cartridge has the same functional dimensions as the popular 9mm Parabellum round, and was designed to produce the same recoil and pressures. This is meant to allow 9mm Parabellum weapons to be converted to 6.5×25mm CBJ with just a simple barrel change. Because it has the same dimensions as the 9mm Parabellum round, the 6.5×25mm CBJ is usable in 9mm magazines.
The primary load of the 6.5×25mm CBJ is a 4mm diameter, 31 grain tungsten sub-projectile in a sabot. The overall weight of the projectile (both the sub-projectile and the sabot) weighs 39 grains. It has a muzzle velocity of 730 m/s from a 4.7 inch (120mm) barrel with a muzzle energy of 533 J (393 ft-lb). From a 12 inch (300mm) barrel, the muzzle velocity is at 900 m/s with a muzzle energy of 810 J (600 ft-lb), and has good armor penetration out to 400 meters.
The tungsten sub-projectile is able to pierce through 9mm of armor plating, leaving a 6mm wide entry hole when fired from a 300mm barrel. By comparison, 5.56×45mm NATO and 7.62×51mm NATO rounds cause little to no penetration in armor of that thickness. From a 300mm barrel, the tungsten sub-projectile has the same trajectory as a 5.56mm NATO round as fired from an M4 carbine and a velocity of 578 m/s (1900 ft/s), which would penetrate CRISAT armor.
- CBJ - Standard load featuring a tungsten sub-projectile encased in a polymer sabot
- CBJ ST - Spoon tip load
- CBJ HET - High energy transfer load with a 39 grain projectile intended for police use
- CBJ Subsonic AP - Armor-piercing load for use with silencers and sound suppressors in special police and military operations
- CBJ TRP (Traning Reduced Penetration) - Training load with similar trajectory to the standard load with reduced penetration ability
- CBJ Blank - Blank load to be operated in blank-firing devices
- CBJ Drill - Inert dummy load for training and drill purposes