BTs perform well when they leave the barrel at less than 3000fps. Anything above that and it’s subject to come apart. So a 165g in a .308 would be perfect but I would not shoot that bullet in a 300 win Mag. I prefer speed and lots of it. So I shoot mono metal bullets a majority of the time. Picking up a 28 Nosler in a week or so. I’m gonna experiment with 140s at around 3750fps 😁