How do I calculate hit detection between 2 lines?

Hi, what happened is that my weapon has Animation to it, and Hit Detection is calculated via RayCast.

During Previous and Current Frame, if the Motion move too fast, then the Object inbetween won't get register as a hit.

My Question is, is there anyway to see if anything between the green Area got hits, BESIDE THESE 2 METHODS

1. Between A1-B2 Do multiple intermediate RayCasts to Points between A2-B2

2. Calculate and Generate MeshCollider, then delete them every Update.

THX in Advance.