An expanding bullet having a one-piece structure has a cylindrical section and a section that is essentially shaped as a truncated cone, with the bullet tip being situated at the end of the latter section, which end faces away from the cylindrical section, and at least one planned breaking point being formed in this section, wherein the section shaped as a truncated cone is divided into segments and has a channel that has a mouth in the region of the bullet tip, wherein the channel has a bell-shaped widened region, which has its greatest diameter in the region of the transition from the cylindrical section to the section shaped as a truncated cone.