Saab Bofors Dynamics CBJ-MS

The Saab Bofors Dynamics CBJ-MS is a personal defense weapon/submachine gun designed and manufactured by Swedish weapon developer CBJ Tech AB, and was also manufactured by Saab Bofors Dynamics. It can be chambered for both 6.5×25mm CBJ and 9×19mm Parabellum cartridges via simple barrel changes.

, the CBJ-MS was supposedly in its final phases of development but no production date had been announced.

Development
The CBJ-MS ("Modular System" ) was first shown in August 2000. It is an unusual weapon in several respects, not the least because it is meant to fulfill the roles of a personal defense weapon, an assault rifle and (with the addition of a proprietary bipod and 100-round drum magazine) a squad automatic weapon.

The gun features a top-mounted Picatinny rail for mounting optics, a progressive trigger for semi- and fully automatic fire, a collapsing wire stock, a grip safety, a threaded barrel, and a hollow foregrip which can be used to hold a spare magazine.

The CBJ-MS is capable of being field-converted to fire one of two types of ammunition. For the purely military role, the weapon fires the proprietary 6.5×25mm CBJ PDW cartridge; but by simply changing the barrel, it can fire 9×19mm Parabellum ammunition for law enforcement, training and other security operations. The 6.5×25mm CBJ cartridge has the same overall dimensions as the 9×19mm cartridge, can be used in the same magazines and generates the same level of recoil.

The projectile used by the 6.5×25mm CBJ can be a normal ball bullet, but can also be a 4 mm tungsten kinetic penetrator held inside a non-disintegrating plastic sabot, fired at a high muzzle velocity of 815 m/s with the ability to defeat most contemporary body armours. It is also claimed to be effective against light vehicle armors on armoured personnel carriers (APCs). Advantages claimed for the 6.5×25mm 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.

During trials, the 6.5×25mm CBJ round completely penetrated through the standard CRISAT vest at a range of 230 m. It is claimed that it is superior than the 5.7x28mm FN and 4.6×30mm HK round out of the FN P90 and HK MP7.

Current cartridge cases are being developed using aluminium. Each 6.5×25mm CBJ cartridge weighs 4.5 g and has an overall length of 29.7 mm. The projectile weight is 2 g. The effective range of the cartridge is stated to be up to 400 m.