Competition bullets don't have to expand or penetrate, they just have to get into the same hole as the previous bullet. Their construction, while requiring great precision and ruthless quality control, is much simpler than that of a hunting bullet, which has to expand and penetrate both, and getting a slug to do this involves complications. The Swift A-Frame, for example, has two cores, not one, and they're bonded to the bullet's jacket to keep everything together. Two cores doubles the chance for an error in manufacture, but since A-Frames are made in small numbers with people constantly keeping track of what's going on, they shoot just fine. If you go to Africa and would like to see your PH smile, tell him you're shooting A-Frames.