Most bullet's will kill no matter what the weight or construction. That doesn't mean they were designed to kill. Take Nosler. The partition has a cult following. What is the need for the bonded bullet? In fact what is the need for two different bonded bullet's? That cup and core was a good idea but I have no idea how well it really works. Has a place. I think they are about half the cost of the partition's and bonded bullet's.The only company I know of that has not got caught up in this bullet race is Speer! They don't make a monolithic bullet or a bonded bullet. But then I have used Speer Hot Core's and I found the core and jacket don't separate! But don't call them a bonded bullet, shoot, they don't cost enough.
OP say's Hornady doesn't tell you what the 75gr HPBT 223 bullet does other than target shoot. Has it occurred that the bullet is designed for just one thing Paper shooting! Lot of people want to take a bullet like that and proove that company's like Hornady don't have a clue what they are doing but, they still buy the bullet's. Pay careful attention now, the 75gr HPBT is designed to be a match bullet, one more time, a match bullet!