Dished vs. Flat Top Punch

I see that lathesmith makes both dished and flat top punches. What purpose is there for a dished top punch?

Thanks in advance for the replies.

A dished punch will center on a bullet ogive or on a meplat but round it slightly. I use a round nose 374 to run lee 30 flat nosed through my 450.

A dished one also works well if putting bullets through the sizer nose first. Many cast bullets have minor imperfections near the sprue, with otherwise clean bases; the dished TP contacts the bullet at the periphery and the center hollow leaves the protruding sprue untouched, with better alignment of the bullet as it starts into the die.

Thanks for the answers!