A new Weapon system
from Sweden.

Text and photos by O. Janson


updated 2007-10-21

Copy right © 2007, Olof Janson.

All rights reserved. No picture or portion of this publication may be reproduced, or supplied in any format without prior written permission.
Additional restrictions on electronic use also apply. Contact the copyright holder for further information.


A new weapon system from Sweden.
The cartridge - 6.5x25 CBJ.
The Weapon system - CBJ MS
How to field strip the CBJ MS






CBJ MS (Modular System)


The development of this weapon system started in USA some 20 years ago. A Swedish engineer with a background of arms development worked with a company in US. He invented a submachine gun called Viking (see picture).

An article in GUN WORLD
July 1986 about the Viking submachine gun.


The Viking submachine gun was chosen by Jane's Infantry to be one of the five submachine guns of many others to represent the US section in August 1983. After a while he left that company and went back to Sweden and Carl Gustaf gun factory.

After some years CBJ Tech AB was founded as an independent company and the development of this gun continued and it became a completely new weapon system.


Front page of GUN WORLD magazine July 1986 on top of a drawing of the new CBJ MS.


There are many types of guns for soldiers suited for different purposes. Since the last century the armies have been looking for one calibre and one gun for the ordinary soldier. With the development of technology the demands for smaller but more effective guns to be used within 400 m range have been raised.

The dream for the armourer is a gun to fulfil the demands for Pistol, PDW (Personal Defence Weapon), Submachine gun, Assault rifle/carbine and Light support weapon! All in one small easy to bring and handy gun! 

Until now it has been just a dream, but now it has been possible by the help of a new advanced high-tech cartridge, incorporating completely breakthrough technologies.


The CBJ MS weapon family.

This modern weapon, CBJ Modular System, is the most versatile on the market. It can take on many different roles with only minor changes on a basic configuration, all easily possible to change back quickly in the field when needed.



Personal Defence Weapon (PDW)


As a PDW it’s very suitable for commanders, car drivers, personal in tanks, pilots, medical orderlies, machine gunners and support personal.

The CBJ MS can very quickly change the barrel to 9x19 mm Parabellum for special purpose use and/or  training. It is enough to change only the barrel.

The weapon’s small size and low weight makes it easy to carry even though impressive powerful firepower.

It can be carried in different types of slings or a holster.


The front grip can easily be replaced with other types of auxiliary equipment like laser,
flashlights and so on.

The CBS MS can also be equipped with picatinny rails on the sides of the receiver for additional special purpose equipment such as laser/IR pointers, flashlights etc.



with Trijicon ACOG sight.
CBJ MS in PDW version

CBJ MS in PDW version


The H&K MP7 with 4.6x30 and the FN P90 with 5.6x28 are far too inferior to be used instead of a 5.56 NATO carbine. A 5.56 NATO with a short carbine barrel is on the other hand inferior to the 6.5x25 CBJ!


FN P90

The H&K MP7 with 4.6x30 and the FN P90 with 5.6x28 are far too inferior to be used,
instead of a 5.56 NATO carbine.


The dilemma for the armourer of today.

The demand for a small but effective Light Assault Weapon is eminent. The trend has been to shorten already existing weapons like US M16 or Russian AK-74. The results you can see on the pictures below - M4 and AK-74U.

This is a double-edged matter. The gun will be shorter, BUT the short barrel will have negative consequences on the bullet’s velocity and its performance. This is a known fact since WWI. Less velocity will result in reduced penetration in hard targets and reduced effect in the soft targets. With other words – bullets fired from these types of weapons will fail to penetrate body armour or be less lethal.

For example David Crane at Defence review says:

 "It's no secret that the performance of both the M4 Carbine and it’s 5.56x45mm caliber have, so far, been somewhat less than outstanding in the war against Al-Queda forces in Afghanistan. In short, the enemy hasn't been dropping quickly enough when they are hit.

Apparently, the M855 has been zipping right through the bad guys, leaving clean holes out the other side."

 The reason for this is the retarded bullet velocity of the 5.56 M855 cartridges when shot from the short barrelled M4 Carbine.


Colt M4 Carbine with Trijicon ACOG

Courtesy of Buddy Hinton

M4 5.56 NATO with 368 mm (14˝ inches) carbine barrel is on the other hand inferior to the 6.5x25 CBJ!

The same is valid for the Russian AKS-74U with its only 210 mm long barrel in 5.45x39 mm.
It uses a bullet of combined steel and lead core with the hollow nose. This weak nose makes the bullet unstable on impact and it tumbles causing increased energy transfer to a soft target.

At lower velocities it the Russians has the same problems like the west with 5.56 NATO.

At lower velocities it also lacks penetration capacity in steel.

The Russians themselves say that the effective range of fire for
AKS-74U is greatly limited by the poor accuracy at extended ranges.

The Solution!

It is in this aspect the new 6.5x25 CBJ really proves itself!

A bullet fired from the CBJ MS 200 mm barrel has a velocity of 830 m/s. Due to its narrow diameter (4 mm = less air resistance) and high density preserves the velocity over longer distances. Besides, the bullet is harder.

These parameters have the effect, that the bullet retains its performance in hard and soft targets
contrary to the short barrelled M4 and AKS-74U.



Assault rifle or carbine.


The light assault weapon will serve well with most fighting personel in combat like special operation units, infantry, Light Antitank Weapon gunners and gun crews.


CBJ MS as Light Assault Weapon (LAW)


On this picture an extra magazine has been inserted into the front grip for rapid reload.



CBJ MS in Light Assault version with an Trijicon ACOG.


On this picture a sound suppressor has been attached, and an extra magazine has been inserted into the front grip for rapid reload.

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Light Support weapon

CBJ MS in the light support weapon configuration with a 100 rounds magazine!

If you want to see this picture even larger click on the image. 


CBJ MS in the light support weapon configuration with a 30 rounds magazine and removable bipod.


In the light support weapon configuration the CBJ MS is equipped with a removable bipod and 100 round magazine. It is very effective in defensive and ambush situations. It is excellent for fighting in narrow areas. The bipod and the big magazine enable stable continuous effective automatic fire up to 400 meters and shorter distances!
This is better than many standard LMG with 7.62 NATO ammunition at 300 - 400 meters!


With the bipod it is easy to shoot with and hit.

One can easily in a second switch back to PDW or LAW configuration if needed by just changing back to standard magazines and removing the bipod.

It works just like a machinegun up to 400 m! Besides, it is easy to control and compares favourably even to weapons like the LMG FN MINI (US M249)!

The CBJ in LMG version is excellent for sustained automatic fire at multiple targets for distances between 200 to 400 meters.

When you are shooting in prone position, all shots will hit the targets just like you are moving a jet of water. The hit factor exceeds standard machineguns of today using bipods.

I can say that I really like the Trijicon ACOG (Advanced Combat Optical Gunsight)! It gives the extra edge to this weapon.


In the light support weapon configuration the CBJ MS is equipped with a removable bipod and 100 round magazine.

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The CBJ MS is a blowback operating weapon that fires from an open bolt. This is the very best for full auto to avoid overheating. However if the customer prefers a replacement bolt group can be installed within seconds and the gun will fire from a closed action by the help of a floating pin.

The bolt with its deeply recessed bolt face, surrounds the cartridge case effectively during extraction.

The bolt handle has an effective design and place. It is the button at the rear end of the receiver. It is easily pulled down and back with a finger. It is easily operated with left or right hand fingers even with gloves.

The same gun can be used in both 6.5x25 CBJ and 9 mm Parabellum. The gun has rather slow rate of full auto which makes it very easy to control. It is a rugged, simple design and very reliable.

The grip safety runs all along the front strap of the pistol grip. It works directly on the sear that blocks the bolt in either cocked or forward position.

The manual operated safety blocks the grip safety in its forward (safe) position when it is pushed to the safe position.

The safety-grip and mag-release, both located on the pistol grip are fully ambidextrous.

Switching between full- and semi automatic fire is controlled by the two step trigger. The first step gives semi automatic fire, and second step full auto.

The weapon is manufactured according modern production methods like metal stamping, investment casting, cold rolling of steel profiles etc.

On top of the receiver a Picatinny rail is fitted for optical sight and other equipment. 


All parts are made of acid proof steel which is even better than stainless steel. This makes the weapon very resistant to corrosion, also when chemical agents are used for decontamination.

The new weapon system CBJ MS is designed in accordance with the most modern high-tech production methods. It is more than a simple firearm – it is a highly flexible weapon system!


The CBJ MS field strips in seven parts in seconds.

Of course - no tools are needed.

CBJ MS receivers under production of prototypes.

Note that they are made of
Stainless "acid proof" steel!

If you want to see how to field strip the gun click HERE>>>>


CBJ Modular System
with accessories.

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CBJ MS - Technical specifications:

Calibre 6,5x25 CBJ and 9x19 Parabellum
Operation principle 1 Blowback, Open bolt.
Operation principle 2 Blowback, Closed bolt with floating firing pin.
Selective fire

Selective fire by pull of a 2-step trigger semi- / full auto

Safety system Manuell safety and grip safety
Cyclic rate of fire ~700 rpm
Magazine capacities 20-, 30-, 100-rounds
Front sight Adjustable for elevation, post
Night sight Tritium (Beta) light in front sight.
Rear sight Ghost-ring type, 3 positions, adjustable f. windage.
Sight options Picatinny rail for any optical system. More Picatinny rails on the sides are optional.
Length retracted  for 6.5x25CBJ / 9mm 363 mm / 333 mm
Length extended  for 6.5x25CBJ / 9mm 565 mm / 535 mm
Barrel length 9 mm Parabellum 170 mm
Barrel length 6.5x25 CBJ 200 mm
Height with 20 rounds magazine 189 mm
Height with 30 rounds magazine 240 mm
Width 44 mm
Weight unloaded 2 800 gram
Weight loaded w. 30 rounds 6.5x25 CBJ 3050 gram
Combat range for 9 mm Parabellum 200 m
Combat range for 6.5x25 CBJ 400 m

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New Infantry Weapon


This little handy weapon and its effective 6.5x25 CBJ ammunition have, as you have understood, outstanding performance. It opens new doors which were blocked before due to old technique.

This system is excellent for close combat and self defence, due to its size. Beside it has unusual penetrating abilities in hard cover or similar objects and still it is lethal.

It easily penetrates an engine block. Just one burst of bullets from this gun will penetrate and break the engine of a car for good together with all soldiers or terrorists driving that vehicle. The car will stop immediately. And this can be achieved even with a pistol (!) in this magnificent calibre! It is like David against Goliath!

The projectiles will easily penetrate the doors or walls of a building. Still the gun is very small and handy. This makes it excellent for combat among buildings, which is one of the most dangerous situations of combat for a soldier.

If it is used with a bipod and 100-shoot magazine, it will also be excellent as a LMG with very light recoil! The bursts of fire will not leave the target.

At short ranges the light recoil enhances the probability of multiple hits of the enemy during full automatic fire, which will have immediate effect, even at longer ranges.

The gun is quite capable out to 400 m and still the projectile will vigorously deliver its message! This distance extends the normal combat range for most man to man fire fights today.

Most likely we have just seen the dawn of a new era in the development of small arms. This little high-tech cartridge opens new roads for the development, especially together with other arms like recoil-less anti-tank and anti-personal systems. Combinations of these will not be heavy any more.

Why not to continue to develop a system like NIVA (New Infantry Weapon from 1970 with Carl Gustaf Gun Factory? (See picture.) This would be something far better than the present US OICW. (Objective Individual Combat Weapon). Update this gun with different types of 45 mm ammunition like explosive and airburst. Add to this a new sight-laser-computer unit or closer at hand a compact rugged 4x telescopic sight with integrated laser range finder together with a clip on NVD or Thermal device.

The battlefield will never be the same again.



This is NIVA XM1970
from Carl Gustaf Gun Factory (FFV).

A combination of Recoilless
45 mm AT and 5.56 assault rifle.


Weight loaded 5.4 kg

Length over all 900 mm

Vo= 900 m/s and 300 m/s

5.56 NATO - 700 rpm

45 mm - 6 rpm


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Commander of Swedish Nationella SWAT for equipment.
Saab Bofors Dynamics
FN Herstal 
Izmash JSC.
Jane's International Defence.
Valery Shilin.





A new weapon system
from Sweden.

The cartridge - 6.5x25 CBJ.


The Weapon system - CBJ MS

How to field strip the CBJ MS