Container (10) is generally cylindrical except for a longitudinal concave
groove (11) extending along its entire length. Upon explosion, the
contour of this groove (11) results in a focussing effect on the wall
material due to the oblique angle at which the expanding cylindrical
detonation wave front impacts upon its inner wall. This produces the
forging of a rough rod-like projectile (11.sub.1) which, being coherent,
maintains its velocity and consequently travels much further than the
randomly shaped projectiles (10.sub.1).