PKD is a master of a certain kind of paranoid vision. He was obsessed with the aftermath of World War 3, self-replicating weapons, the reality of a man. All these themes come together in what I believe is his best short story, a taut thriller of soldiers surviving in an atomic wasteland inhabited by autonomous robot Claws. I won't spoil the ending, but it is short, most excellent, and available for free at www.manybooks.net. Why haven't you read it already?