I’m afraid that this is mathematicallly not possible then.
It isnt too hard to imagine the situation, you can’t fire a projectile with a spawn location different location and pass infinite points on a different line, your crosshair line. It is not possible, not just programmatically, mathematically.
Just imagine a cube in front of your character directly in the center. Now walk 1000m back. The cube will still be under your crosshair. But your weapon would have to aim differently to hit it.