VB rifle grenade

The Viven-Bessières rifle grenade, named after its inventors, also known as "VB grenade", and officially referred to as the "Viven-Bessières shell" in the French Army instruction manual, was an infantry weapon in use with the French Army from 1916 onwards.

This grenade launcher consists of two elements, the discharger and the projectile.

Having a diameter of 50 mm (2.0 in), it weighs about 1.5 kg (3.3 lb). It is fitted on the end of the barrel.

When not in use, it was transported in a leather or canvas case. These cases were made by each regiment.

Cylindrical in shape, it was made of cast iron with internal grooves to facilitate fragmentation during its bursting. Its weight is about 490 g (17 oz) (depending on the version). It contains 60 g (2.1 oz) of cheddite.

It has two internal tubes. The first, central, allows the passage of the ball (bullet) of the cartridge that launches the grenade. The second contains the detonator.

It is launched by firing a normal cartridge, the ball (bullet) passing through the tube at the centre of the projectile. In passing, it causes the fuze to ignite, which will cause it to explode about 8 seconds later. The gases generated by the firing of the cartridge are enough to propel the grenade.

There are also Brandt-type projectiles for sending a written message. This projectile emits yellow smoke to improve its recovery. Other versions are smoke or illumination projectiles. These different types of projectiles must be fired with a special blank cartridge, without a bullet.