This is excellent Phil. What we as hunters need to understand is that bullets are designed to preform differently. As EXAMPLE, Barnes TSX and Nosler Partitions are very different bullets and designed to preform very differently under different conditions. IMO Both are excellent bullets when used under the conditions for which they are designed. But both also experience failures when they are used in applications they are not designed for.
IMO when Hornaday bullets are used in the application and optimum thresholds for which they designed, they preform very well. If impact energy is pushed, they it appears they will come apart. I personally would not take that chance. And, I also would not take the chance with with a TSX bullet in a rifle with a low impact energy either.
Use bullets that are designed to preform based on what the specific application is and do not stretch those limits on the upper or lower end of the design.