What's the problem with this Velocity script?

I'm trying to make a part zoom towards the Mouse/Lookvector at a certain speed.

function Shoot()
local Part = Instance.new("Part", human)
Part.Name = "Bullet"
Part.Position = human.Torso.Position
Part.FormFactor = 1
Part.Size = Vector3.new(0.25, 0.25, 0.25)
Part.Velocity = Vector3.new(CFrame.lookVector*5)
end