A warhead configuration for forming a hole through a wall of a target, the warhead configuration comprising a charge of explosive material and a liner. The charge has an axis and a front surface. The front surface includes two annular front surface portions, an inner and an outer annular portion, circumscribing the axis. Each of the annular front surface portions is configured so as to exhibit a concave profile as viewed in a cross-section through the charge parallel to the axis. The liner includes a first liner disposed adjacent to the inner annular portion and a second liner disposed adjacent to the outer annular portion such that, when the charge is detonated, material from the first liner is formed into a first expanding explosively formed ring and material from the second liner is formed into a second explosively formed ring.