A projectile (10) is for use with barrel assemblies of the type having a plurality of projectiles axially disposed within a barrel having a bore and a muzzle and which projectiles are associated with discrete propellant charges for propelling said projectiles sequentially through the muzzle of the barrel. Projectile (10) comprises expandable sleeve (11) encircling at least part of core (12). Sleeve (11) and core (12) have wedging surfaces (14) operable to deform trailing part (21) of sleeve (11) into sealing engagement with the bore in response to pressure exerted on the projectile (10). When projectiles (10) are axially disposed in the bore, rear face (24) of the leading projectile cooperates with leading face (20) of the trailing projectile to define a discrete space about spine (23) for receipt of the propellant charge. Sleeve (11) is retained about the core (12) during travel to the target.