Armor piercing shell of the APBC
1 Light weight ballistic cap
2 Steel alloy piercing shell
3 Desensitized bursting charge (TNT, Trinitrophenol, RDX...)
4 Fuse (set with delay to explode inside the target)
5 Bourrelet (front) and driving band (rear)
The basic make up of a APBC round used during WW2.
ack-ack