What's causing my magic beam and projectile aim to go wacky when it doesnt hit a base part?

Ill only include beam code here, since the projectile script is pretty similar.

Hierarchy: StarterPack --> Tool --> LocalScript(Main) --> RemoteEvent(Function) --> Script(Handle) --> Bunch of particles

Here in the LocalScript(Main), I'm getting a userinput and on E press, I pass the mouse.hit.p to the remoteevent

game:GetService("UserInputService").InputBegan:Connect(function(input)
if input.KeyCode == Enum.KeyCode.E and equipped == true and eCoolDown == false and isTyping == false and mainCoolDown == false then
        local BG = Instance.new("BodyGyro", humanoidRootPart)
        BG.maxTorque = Vector3.new(250000, 250000, 250000)
        BG.P = 6000
        BG.D = 150

        local BP = Instance.new("BodyPosition", humanoidRootPart)
        BP.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
        local pos = humanoidRootPart.Position
        BP.P = 6000
        BP.D = 150

        script.Function:FireServer("KeyDown", "E")
        keydown = true
        local timer = 45
        while keydown and timer > 0 do
            BP.Position = pos
            BG.CFrame = CFrame.new(humanoidRootPart.Position, mouse.hit.p)
            timer = timer - 1
            wait()
        end
        local firePosition = mouse.hit.p
        wait(0.3)

        spawn(function() 
            wait(1.2)
            BP:Destroy()
            BG:Destroy() 
        end)
        script.Function:FireServer("KeyReleased", "E", firePosition)
        mainCoolDown = true
        spawn(function() wait(1.3) mainCoolDown = false end)
        eCoolDown = true
        wait(2)
        eCoolDown = false
    end
end)

Script(Handle) receives and creates the laser beam

keydown = false
mousePosition = nil
RegMod = require(game.ReplicatedStorage.RegionModule)
onCooldown = false

script.Parent.OnServerEvent:Connect(function(player, command, ability, LastMousePosition)
    local c = player.Character or player.CharacterAdded:wait()

    if command == "KeyReleased" then
        keydown = false
        mousePosition = LastMousePosition
    end

    if command == "KeyDown" then
        keydown = true
        while keydown do
            wait(0.03)
        end
if ability == "E" then
            local Beam = Instance.new("Part", game.Workspace.Beams)
            Beam.Shape = "Cylinder"
            Beam.BrickColor = BrickColor.new("Bright orange")
            Beam.Material = "Neon"
            Beam.Transparency = 0.1
            Beam.CanCollide = false
            Beam.Anchored = true
            Beam.CFrame = c.HumanoidRootPart.CFrame 
            Beam.CFrame = CFrame.new(c.HumanoidRootPart.Position, mousePosition) * CFrame.Angles(math.rad(0),math.rad(-90),math.rad(0))
            Beam.CFrame = Beam.CFrame * CFrame.new(-2.5,1.5,0)
            Beam.Size = Vector3.new(0.1,0.1,0.1)

            local ignore = {c, workspace.Beams, workspace.FX, workspace.Junk, workspace.Projectiles}
            local RayStart = c.HumanoidRootPart.Position
            local RayEnd = mousePosition
            local Length = 200
            local FireRay = Ray.new(RayStart, (RayEnd-RayStart).unit*Length)
            local HitPart,BeamPosition = game.Workspace:FindPartOnRayWithIgnoreList(FireRay, ignore)

            print(CFrame.new(c.HumanoidRootPart.Position, BeamPosition))
            print(CFrame.new(c.HumanoidRootPart.Position, mousePosition))
            print(CFrame.new(c.HumanoidRootPart.Position, Beam.CFrame.Position)) 
            --These all print the same thing, so I think the error has to do with where mouse.hit.p actually is

            local BeamLength = Instance.new("NumberValue", Beam)
            BeamLength.Name = "BeamLength"
            BeamLength.Value = (BeamPosition - c.HumanoidRootPart.Position).magnitude

            --Rest of the script just registers damage and effects
    end
end)

https://gyazo.com/3e11885d71c3dedde63aadaf73b4fa5f

Especially in the second cast, you can see the error. Any help would be appreciated :^)