How to change gravity for actors

Is there any way to change the custom gravity for actors like there is a change for characters?

If not, is there anyway to write a system that can replicate it?

I’m looking for the same thing (to set a projectile to have no gravity, until it hits something, and then give it gravity so it bounces off and falls).
At the moment the only way I can think of doing it is to spawn a zero-gravity bullet on firing, destroy that on impact and spawn a new actor there that is effected by gravity. But then I don’t know how to give it the bounce the original actor had.