Take a given bullet and push it faster, the faster you push it, the more damage it will do.
Fine examples will be
a .22lr and a 22-250
a .308 and a .300 UM
a .50 ML and a 50 BMG
But theres a lot of variables as to whats better. A 50 gr bullet at 3500fps is not better than a 180gr at 2700fps but a 180gr is better at 3500fps.
And then theres penetration, take a 180gr sp bullet , it will penetrate more at 2600fps then at 3500 fps.
Things start to blow up with anything above 2500 fps, anything above 3500 fps and weird stuff starts to happen