6.5x25 CBJ - The new rifle cartridge in a pistol cartridge size

The new 6.5x25 CBJ is a high performance cartridge system with the following key characteristics:

High velocity, V₀ of 730 - 900m/s depending on barrel length
Optional penetration, from minimal to extreme
High hit probability due to low recoil and good ballistic performance
High wounding effect
High system flexibility

Weapon effectiveness

There are many factors that constitute weapon effectiveness, other than bullet performance in bare tissue even if this, of course, is critical. Weapon effectiveness can be defined as the ability of a soldier or police officer armed with a certain weapon system (weapon and cartridge) to defeat an enemy. This in turn is a function of how well the weapon system is adapted to the skills of the person using the weapon, the characteristics of the target and the combat environment. Focusing on the weapon system, this means there are three main aspects to consider, which are as follows in order of importance.

The ability to hit the target.
To have sufficient penetration to defeat barriers protecting the target and then penetrate deep enough in the target to reach vital structures to incapacitate reliably.
To have a high energy transfer to the target in order to increase the chance of rapid incapacitation.

Pistols and submachine guns are weapons with distinct benefits such as low weight, compact size and, in the case of submachine guns, high firepower. However, in modern combat these weapon systems, mainly based on the 9x19 Parabellum round, are proving less effective because of lack of penetration, limited effective range and poor wounding power.

Assault rifles are increasingly used for applications that used to be typical for submachine guns, like close quarter battle etc. On the other hand, assault rifles too have important limitations. Firepower is reduced due to higher recoil and there are problems with overheating. They are heavy, and due to their length awkward to handle in vehicles and confined spaces. Attempts to make them more compact by shortening the barrel have resulted in significantly reduced wounding power, due to reduced muzzle velocity.

How the 6.5x25 CBJ solves it

Realizing this, CBJ Tech AB has developed a cartridge system based on the new caliber 6.5x25 CBJ. In combination with suitable weapons, the 6.5x25 CBJ covers the full range of applications traditionally covered by everything from pistols up to and in most cases including short assault rifles, and offers high firepower and superior penetration and wounding power at full combat ranges in any combat situation.

According to the criteria for weapon effectiveness stated above, the following applies for the 6.5x25 CBJ cartridge system:

Hit probability is increased because of the low recoil generated, allowing rapid firing at high precision, and in the case of fully automatic weapons, the ability to fire accurate bursts. Also, at longer ranges and at moving targets the high retained velocity of the bullet with resulting flat trajectory and short time of flight to the target reduces the need of compensation, which greatly simplifies aiming.
The required penetration depends on the situation. For instance, the combat soldier generally needs more penetration than the average police officer. Within the 6.5x25 CBJ cartridge family, the entire spectrum of penetration is covered, from maximum penetration against tough targets to minimum penetration against unprotected targets in sensitive environments.
The different variants of the 6.5x25 CBJ have high energy and effective means to transfer it to soft tissue, resulting in a high wounding effect.

The 6.5x25 CBJ cartridge is of course primarily intended to be used in weapons designed and optimized for this caliber. However it is also designed to be used in 9x19 Parabellum weapons, converted by barrel change to the 6.5x25 CBJ. The cartridge generates the same level of impulse as the 9x19 Parabellum, which assures functioning of the weapons. The bolt face, groove and cartridge case up to the shoulder of the 6.5x25 CBJ are identical to the 9x19 Parabellum, as is the total length of the cartridge, 29.7mm.

This makes the transition to the new caliber easy. Another benefit is that existing stocks of 9x19 Parabellum ammunition can still be used for training instead of being scrapped.

There are many different potential users for the 6.5x25 CBJ, primarily within the military and law enforcement sector, with accordingly different demands. This includes personnel armed with pistol or PDW for personal defense and regular police units, as well as units with offensive tasks, like SWAT, Special Forces, units specialized in urban warfare, Security Forces etc.

In order to be highly effective in all situations, the 6.5x25 CBJ has several cartridge alternatives, none of which contains any toxic material.

For training, there are cost effective alternatives. For combat, there are different cartridge alternatives depending on the situation and desired performance.

The development of the combat ammunition has followed a number of criteria, mainly:

The bullet shall be effective within the entire desired combat range
It must be able to penetrate any reasonable barrier typical for the application without breaking apart
After penetrating such barriers it has to be able to penetrate at least 30cm of soft tissue to cause reliable incapacitation from any angle of impact
After achieving the above, it shall have as high energy transfer to the target as possible

To assure effectiveness, extensive testing has been conducted. A comprehensive overview of this can be found at the Testing Page.

Logistical benefits

Many tactical benefits granted by the 6.5x25 CBJ stems from high firepower, that is the ability to accurately fire many rounds in a short period of time. This however requires that an ample supply of ammunition can be carried by the soldier without increasing weight or bulk.

In a pouch designed for 5.56 NATO magazines, as seen on the picture below, twice as many magazines and rounds of the 6.5x25 CBJ or 9x19 Parabellum can be stored. The picture shows three 30 round 5.56 NATO magazines in one pouch, and six 30 round 6.5x25 CBJ magazines in the other identical pouch. Regarding weight, not only the weight of the ammunition itself but also the weight of the weapon has to be considered.

A typical 7.62 NATO assault rifle with 100 rounds in magazines weighs approximately 8.4kg. At the same weight a 5.56 NATO assault rifle allows for up to three times more ammunition to be carried, as seen in the picture below. A submachine gun weighing 3kg, like the CBJ MS, chambered for 9x19 parabellum will allow even more rounds to be carried, owing to the lighter weight of the weapon. When the same weapon is chambered for the 6.5x25 CBJ the amount of ammunition that can be carried is three times that of a 5.56 NATO weapon system, or nine times that of a 7.62 NATO system.

Technical Data

Seen below is a chart that shows a comparison of different projectiles zeroed on 100m and 200m. The scale on the Y-axis is in mm and the scale on the X-axis is in m.

Published data was used for the 4,6x30 and SS190.