How to make 2.5D Side Scroller aim weapon at mouse cursor?

I am trying to get my character’s weapon to aim towards the position of my mouse. Here is the blueprint I am using:

This works, but only in orthographic camera view. I need it to work for perspective view, since my game is taking place in 3D, and I’m not sure how to do it. Any tips will be greatly appreciated.

How’s this: