EURENCO also provides spherical powders and single base propellant for rimfire ammunition.
In a rimfire cartridge, the gunpowder or propellant is inside the main body of the cartridge, but the primer material (i.e. the shock-sensitive material) is placed throughout the rim at the base of the cartridge. To fire this, one must strike the rim of the cartridge with a sharp blow. The shock-sensitive chemicals inside will detonate with the force of the blow and spread the flame throughout the gunpowder, thereby discharging the bullet.
The material on the rim of the cartridge has to be somewhat thin so that it can be deformed by the hammer to detonate the cartridge. This means that the cartridge itself cannot withstand too much pressure and can only be used for low-powered weapons.