CFraming OBJECT SPACE upwards?

Hi. I have been messing around with the default raycast gun script and I want the laser to get smaller and move forward. Here is my current code:

local tool = script.Parent

--when the tool is equipped
   --store the character of the person using the tool
   user = tool.Parent 
   mouse = game.Players.LocalPlayer:GetMouse()
   --when the left mouse button is clicked
   mouse.Button1Down:connect(function() 
       --make and do a hit test along the ray
       if script.Parent.AbleToFire.Value == true then
       print('RAYSENT')
       local ray = Ray.new(tool.FireFrom.CFrame.p, (mouse.Hit.p - tool.FireFrom.CFrame.p).unit*300)
       local hit, position = game.Workspace:FindPartOnRay(ray, user)

       --do damage to any humanoids hit
       local humanoid = hit and hit.Parent and hit.Parent:FindFirstChild("Humanoid")
       if humanoid then
           humanoid:TakeDamage(30)
       end

       --draw the ray
       local distance = (position - tool.Handle.CFrame.p).magnitude
       local rayPart = Instance.new("Part", workspace)
       rayPart.Name          = "RayPart"
       rayPart.BrickColor    = BrickColor.new("Bright red")
       rayPart.Transparency  = 0.5
       rayPart.Anchored      = true
       rayPart.CanCollide    = false
       rayPart.TopSurface    = Enum.SurfaceType.Smooth
       rayPart.BottomSurface = Enum.SurfaceType.Smooth
       rayPart.formFactor    = Enum.FormFactor.Custom
       rayPart.Size          = Vector3.new(0.2, 0.2, distance)
       rayPart.CFrame        = CFrame.new(position, tool.FireFrom.CFrame.p) * CFrame.new(0, 0, -distance/2)

       --add it to debris so it disappears after 0.1 seconds
       wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       game.Debris:AddItem(rayPart, 0.1)
       end
   end)


function Equipped()
    script.Parent.AbleToFire.Value = true
LeftArmFireCF = CFrame.new(.84, .4, 1.1) * CFrame.fromEulerAnglesXYZ(math.rad(320), -0.2, math.rad(-90))
RightArmFireCF = CFrame.new(-.75, -0.4, -0.95) * CFrame.fromEulerAnglesXYZ(math.rad(-89), math.rad(-14), 0)
LeftArmWeld = Instance.new("Weld", script)
RightArmWeld = Instance.new("Weld", script)
local Char = game.Players.LocalPlayer.Character
    if Char:findFirstChild("Left Arm") ~= nil then
        LeftArmWeld.Parent = script
        LeftArmWeld.Part0 = Char["Head"]
        LeftArmWeld.Part1 = Char["Left Arm"]
        LeftArmWeld.C1 = LeftArmFireCF
        Char["Torso"]["Left Shoulder"].Part1 = nil
    end
    if Char:findFirstChild("Right Arm") ~= nil then
        RightArmWeld.Parent = script
        RightArmWeld.Part0 = Char["Head"]
        RightArmWeld.Part1 = Char["Right Arm"]
        RightArmWeld.C1 = RightArmFireCF
        Char["Torso"]["Right Shoulder"].Part1 = nil
    end
end

function UnEquipped()
        script.Parent.AbleToFire.Value = false
coroutine.resume(coroutine.create(function()
    local Char = game.Players.LocalPlayer.Character
    if Char:findFirstChild("Left Arm") then
        LeftArmWeld.Part0 = nil
        LeftArmWeld.Part1 = nil
        Char["Torso"]["Left Shoulder"].Part1 = Char["Left Arm"]
    end
    if Char:findFirstChild("Right Arm") then
        RightArmWeld.Part0 = nil
        RightArmWeld.Part1 = nil
        Char["Torso"]["Right Shoulder"].Part1 = Char["Right Arm"]
    end
end))
end



script.Parent.Equipped:connect(Equipped)
script.Parent.Unequipped:connect(UnEquipped)

Right now, I fire the ray and the trace, the trace works for 0.1 ticks, then it goes and has a fit in the other direction.

How could I get it to move forward through the objects perspective. The code that I try to do this with is here:

wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       rayPart.Size = rayPart.Size - Vector3.new(0.2,0.2,distance/3)
       rayPart.CFrame = rayPart.CFrame * rayPart.CFrame:toObjectSpace(CFrame.new(0, distance/3, 0))
       wait(0.1)
       game.Debris:AddItem(rayPart, 0.1)

Any help would be greatly appreciated!

Thanks!

P.S. No errors before you ask.