How would i make "Laserbeam bullets" with fastcast

Basically i want the bullets to be the entire length of the ray, or something
image

Some Examples would be like
R2da’s laser bullets
Possibly dahood’s bullets
ill add more examples when i can think about what else has laser bullets

(edit)

Something like how aim h4x does it

It might be better to not use fastcast for this issue, because of how fastcast works it shoots multiple rays one by one at a velocity until it reaches your destination. And having one bullet that starts at the barrel of your gun and ends directly at the end position in no time is viable only with default workspace:RayCast() usage where it casts from start to end immediately.

Alright ill change my code to use normal raycast instead of fastcast