Saab Bofors Dynamics CBJ MS personal defence weapon
The Saab Bofors CBJ MS personal defence weapon was first shown during late August 2000. It is an unusual weapon in several respects, not least that it is meant to fulfil the roles of personal defence weapon, assault weapon 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 x 25 mm CBJ cartridge but, by simply changing the barrel, it can fire 9 x 19 mm Parabellum ammunition for police, training and other operations. The 6.5 x 25 mm CBJ cartridge has the same overall dimensions as the 9 x 19 mm Parabellum cartridge and generates the same level of firing impulse. The projectile is a tungsten insert held in a plastic sabot, creating 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. Advantages claimed for the 6.5 x 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 x 25 mm CBJ cartridge weighs 4.5 g and the overall length is 29.7 mm. The projectile weight is 2 g. Combat range of the cartridge is stated to be up to 400 m.
The Saab Bofors CBJ MS personal defence weapon is an extremely compact weapon only 363 mm long with the telescopic wire butt-stock retracted; extended length is 565 mm. In overall appearance the weapon resembles a Mini-Uzi with the main difference being the addition of a forward grip that can accommodate a spare magazine.
The basic operating principle is straightforward blowback from an open breech, with a fixed firing pin. As a special option this could be altered to blowback from a closed breech with a floating firing pin. Manual and grip safeties are provided. Fire mode selection is via the trigger. A slight pressure produces semi-automatic fire while further definite pressure results in fully automatic fire. The cyclic rate of fire is approximately 575 rds/min.
Ammunition is fed from 20- or 30-round box magazines, the 20-round magazine length matching that of the pistol grip. Also available for the light support role is a 100-round drum magazine. Ammunition is supplied in 30- or 36-round clips together with a magazine loading device. A spent cartridge receiver bag is available.
Changing from 6.5 x 25 mm CBJ to 9 x 19 mm Parabellum calibre involves changing the barrel only. This is accomplished by simply unscrewing the barrel locking nut and changing the barrel, the operation being completed once the locking nut is tightened. The 9 mm barrel can accommodate a tubular titanium suppressor. A clip-on bipod can be added when the 6.5 mm CBJ MS is employed in the light support role.
A length of MIL-STD-1913 Picatinny rail is provided over the receiver to accommodate optical or night sights. A typical optical sight is a x1.5 Trijicon unit. Iron sights are provided, the foresight having a tritium light for use at night or under poor visibility conditions. One combat accessory is a flashless and smokeless grenade launcher that clips onto a rail to be used with 6.5 or 9 mm ammunition. The grenade involved weighs 230 g with HEAT, HE, smoke, flash/bang or tear gas payloads. Muzzle velocity is more than 80 m/s.
Cartridge: 6.5 x 25 mm CBJ or 9 x 19 mm Parabellum
Operation: blowback from open or (option) closed breech; selective fire
Feed: 20- or 30-round box; or 100-round drum magazines
Weight: empty, 2.65 kg; loaded, 30 rounds 6.5 mm CBJ, 2.9 kg
Length: stock retracted, 363 mm; stock extended, 565 mm
Sights: fore, post, adjustable for elevation; rear, 3-position aperture, adjustable for windage; tritium light on front sight
Muzzle velocity: ca 815 m/s; at 200 m, ca 632 m/s; at 400 m, ca 468 m/s
Combat range: 6.5 mm CBJ, 400 m
Saab Bofors Dynamics AB
Pic1 Saab Bofors CBJ MS personal defence weapon with optical sight and butt retracted; the 9 mm barrel can be seen placed just above the optical sight (C Cutshaw) (2001)
Pic2 Saab Bofors CBJ MS personal defence weapon with optical sight and butt extended; a 30-round magazine is in position in the foregrip (C Cutshaw) (2001)
Pic 3 For comparison, a 6.5 x 25 mm CBJ cartridge is on the right with a 9 x 19 mm Parabellum cartridge on the left (C Cutshaw) (2001)
Picture and information courtesy of:
Janes Infantry Weapons