Continuing a CFrame past the end destination in the same direction, relative to start position?

How do I go about this? I’ve tried multiplying the CFrame by distance but that’s wrong, I know. Basically, I want to shoot a bullet from Position A, and have it travel to Position B(From mouse hit position), however I want it to continue past this point. I’ve used BodyForce but I’d prefer tweening the position and having the positions. I also want to incorporate Raycasts for server side hit detection, and I am struggling to make the raycast go in the direction I want it to go, along a long distance.