Cast kills as well as jacketed in large bores.
It's not necessarily exclusive to "large bores", it just isn't as simple.
It's been the better part of 80 years to get jacketed stuff in the wee calibers to hold together enough, especially when velocity is upped and SD is lessened.
Obviously when the splat factor of the alloy and velocity are understood, lead responds like jacketed, with less speed. Up the speed to jacketed levels, lead will need a bit more gymnastics, but it is there if one goes through the trouble.
