You have to be careful with a round ball expanding too fast and not getting the penetration. That's why I don't shoot too heavy of a load. A half inch hole through both lungs is a kill. That would be with no expansion.
Swiss 3F is a strong powder. It doesn't take as much as someone using 2F Goex. I understand a flatter trajectory is handy, but terminal performance is more important.
Good luck with the cow hunt. My favorite meat.