In William Golding's "Lord of the Flies," Jack starts using a spear as he becomes increasingly consumed by the hunt and the desire for power. This transition is significant and can be traced primarily in Chapter 4, titled "Painted Faces and Long Hair."
While I can't provide specific page numbers or direct quotes from the text, I can summarize that Jack and his hunters use sharpened sticks (spears) for the first time during a hunting scene in this chapter. Their descent into savagery is marked by the use of these weapons, which they create for hunting pigs. The imagery of them standing with their spears is a key moment that underscores their transformation and loss of innocence.
Feel free to look up Chapter 4 for more detailed passages that illustrate this shift!