A cartridge assembly (10) for firearms or weapons, said cartridge assembly including a support body (11) having a central longitudinal channel (16) housing a plurality of projectiles (20, 22, 24) in end-to-end orientation and having a plurality of circumferential chambers (14), wherein each chamber houses (14a, 14b, 14c) at least one propellant charge (12a, 12b, 12c) and is located adjacent to a respective projectile; fluid communication means (18) included in the support body for communicating the products of a gaseous expansion of said propellant from a respective chamber (14) into said central longitudinal channel (16); whereby, upon initiation of a selected propellant charge (12a, 12b, 12c), the communicated products of gaseous expansion from a circumferential chamber force or eject a respective projectile (20, 22, 24) from the cartridge assembly (10). The propellant charges may comprise a volume of propellant material encased in a bag with an igniter.