6.5×25mm CBJ
The 6.5×25mm CBJ is a Swedish cartridge developed by CBJ Tech AB for the CBJ-MS personal defense weapon. It was designed to match the size, recoil, and pressure of the 9×19mm Parabellum so many 9 mm guns could be converted with just a barrel change and used with the same magazines. Named after founder Carl Bertil Johansson, the standard round uses a saboted tungsten penetrator: a 2 g (31 gr) 4 mm (0.16 in) diameter core inside a sabot, giving a total round weight of about 2.5 g (39 gr).
From a 120 mm barrel it fires at about 730 m/s (2,400 ft/s) with around 533 J of energy. From a 300 mm barrel, velocity rises to about 900 m/s (3,000 ft/s) with around 810 J. The round can penetrate armor out to about 400 m (440 yd). The saboted round can pierce about 9 mm (0.35 in) armor plate from a 300 mm barrel, leaving a 6 mm (0.24 in) entry hole. In comparison, the 6.5×25mm CBJ from the same barrel length has a similar trajectory to 5.56×45mm NATO from an M4 and can reach 578 m/s (1,900 ft/s) at 300 m, which allows it to penetrate CRISAT armor. The brass-jacketed ball versions are heavier than comparable FN 5.7×28mm or HK 4.6×30mm rounds. In a pistol, the round can penetrate about 7 mm (0.28 in) of armor plate.
Variants include a spoon-tip loading to encourage cavitation on impact, a high-energy-transfer (HET) round, a training/low-penetration version (TRP), a subsonic armor-piercing round for suppressors, a frangible round, a blank, and a drill round.
Key specs:
- Parent case: 9×19mm Parabellum
- Case type: Rimless, bottleneck
- Bullet diameter: 0.157 in (4.0 mm)
- Overall length: 1.169 in (29.7 mm)
- Primer: Large pistol
Note: This summary focuses on the cartridge design, performance, and its variants.
This page was last edited on 2 February 2026, at 16:58 (CET).