Shrapnel shell contained a number of lead-antimony balls; the antimony hardened the lead and gave it better penetrating qualities. The fuze on the nose burned as long as it was set for, then burned down the powder trail through the center of the shell, which exploded the bursting charge at the base. This blew the balls and the fuze out the nose. If a shrapnel shell exploded properly, the shell case will still be intact today. The bursting charge was only thatit was only meant to push the balls out of the shell and scatter them forward, not fracture the shell body and send fragments in all directions.
Source: H. A. Bethell, Modern Artillery in the Field