A projectile including an elongated tubular body having an open fore end portion defining a gun bore and an intermediate portion defining a chamber communicating with the gun bore for receiving an ammunition cartridge. A firing pin is slidably disposed within the tubular body rearwardly of the chamber therein and is adapted to be shifted forwardly within the tubular body to engage the primer of an ammunition cartridge housed within the chamber upon fore end contact of the projectile body with a target to cause detonation of the ammunition cartridge.