IMO, the original TBBC sucked, it built up too much pressure so quick, it was like a naked barnes X. It copper fouled a barrel so bad, it took an hour to get it out. And they wasn't the most accurate bullets in the world usually. So if they found a way to make them copper foul less, be more dynamic in various barrel diameters, like the TSX, and better BC, then they will have a winner. I have loaded the TSX since it came out, and performance on game is great. But would trust the carter design more. All shots with the TSX has been shoulder shots which really tore thru like a tornado. Now, the orig. TBBC did perform awesome on a moose for me several years ago. Just very finicky, they were hard to find even on the net to order.