I've lost count of how many bull elk I've taken in my lifetime or how many I've seen taken, but it has to be well over 100 and could be over 200. The most predictable bullet design I've seen is the Barnes X style of bullet, be they original X or TSX. Folks tell me that the TTSX is no different and after speaking with Barnes about the TTSX, I believe it is no different terminally than the other two X styles. There are a lot of great premium bullets designs out there and even some of the cup & core designs work great on elk,withing certain perameters, but the Barnes X style is the most predictable and repeatable that I have experienced for expanding type game bullets.