The Saab Bofors Dynamics CBJ-MS is a personal defense weapon/submachine gun manufactured by Saab Bofors Dynamics for Sweden. It is chambered for both 6.5×25 CBJ and 9×19mm Luger/Parabellum cartridges.
The Saab Bofors CBJ MS was first shown in August 2000. It is an unusual weapon in several respects, not least because it is meant to fulfill the roles of PDW, assault rifle and light support weapon. It is also capable of being field-converted to fire one of two types of ammunition. For the purely military role, the CBJ MS fires a new 6.5 × 25 mm CBJ cartridge; but by simply changing the barrel, it can fire 9 × 19 mm Parabellum ammunition for police, training and other operations.
The 6.5 × 25 mm CBJ cartridge has the same overall dimensions as the 9 × 19 mm cartridge and generates the same level of firing impulse. The projectile is a tungsten insert held in a plastic sabot, fired at a high muzzle velocity (815 m/s) with the ability to defeat current and future body armours. It is claimed to be effective against lightly armoured vehicles such as armoured personnel carriers (APCs).
Advantages claimed for the 6.5 × 25 mm CBJ cartridge include a high impact velocity, a high hit probability due to the flat trajectory, high energy transfer to the target, and low levels of barrel wear and corrosion. The cartridge case is aluminium. Each 6.5 × 25 mm CBJ cartridge weighs 4.5 g and has an overall length of 29.7 mm. The projectile weight is 2 g. The combat range of the cartridge is stated to be up to 400 m.