Other than Actor being capitalized after the if check (which it shouldn't be), it might be because the check isn't getting the actor. Distance is to the center of the actors torso, so if you shoot him in the face or another extremity, it might not reach him, though a shot in the torso would kill any vanilla actor. The code seems functional, so try fixing the capital A first. We all know how rigid CC is about capital letters.

If you want it to work on bigger actors you can change this



to



You might want multiply it by 2.5 or 3 instead

It'd probably be easier to use something like a ray check based on velocity and a findrootmo. That way you'd make it more reliable and also able to work on large actors without oddness cropping up. You can balance it out with additional conditions from there, if you please.

I would divide by mass instead, otherwise you get rapid health deflation and bigger actors take longer to kill.