|Place of origin||Sweden|
|Manufacturer||CBJ Tech AB|
CBJ ST (spoon tip)
CBJ HET (high energy transfer)
CBJ Subsonic AP
CBJ TRP (training reduced penetration)
|Case type||Rimless, bottleneck|
|Bullet diameter||0.157 in (4.0 mm)|
|Overall length||1.169 in (29.7 mm)|
|Primer type||Large Pistol|
The 6.5×25mm CBJ is a pistol cartridge designed for the CBJ-MS personal defence weapon. Capable of use in rebarreled 9×19mm Parabellum firearms, the primary loading of the round fires a sabotted 4 mm tungsten sub-projectile.
The 6.5×25mm CBJ has the same functional dimensions as the 9×19 Parabellum and was designed to produce the same recoil and pressures to allow most 9mm weapons to be converted to 6.5×25mm CBJ with a simple barrel change.
Because the 6.5×25mm CBJ has the same overall dimensions as the 9×19 Parabellum, it can be used in 9 mm magazines. The standard ball round fires a saboted tungsten 2 g (31 gr) 4.0 mm diameter sub-projectile, weighing 2.5 g (39 gr) with the sabot. It has a muzzle velocity of 730 m/s (2,400 ft/s) from a 120 mm (4.7 in) barrel with a muzzle energy of 533 J (393 ft·lb). From a 300 mm (12 in) barrel, it has a muzzle velocity of 900 m/s (3,000 ft/s) with a muzzle energy of 810 J (600 ft·lb), 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. From a 300 mm 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. 6.5×25mm CBJ rounds are faster and heavier than both 5.7×28mm and 4.6×30mm.
There are several other 6.5×25mm CBJ bullets other than the sabot in full-caliber. Military rounds include a "spoon-tip" loading that increases the chance of the bullet to yaw on impact, and a cheap training version with a different core material. Police rounds include a 2.5 g (39 gr) high-energy-transfer round that can penetrate CRISAT armor at up to 50 meters, and a frangible round for training and situations for minimal barrier penetration. A subsonic armor-piercing round weighs 8 g (120 gr) for use with a suppressor.