Aim Animation - How to do it?

So I am making a gun and I am in the final stages of development. The only thing that I really really need is an aiming animation. I cannot for the life of me figure out how to do it. I could do it the last time I made a gun, and now I can't. Things To Know 1. I have the arms welded to the head (so that they will move up and down relatively with the mouse) 2. I have the fake arms welded to the regular arms. 3. I also have the head welded to the torso to prevent the default animations from happening.

Code for the arm weld and head weld:

local function Weld()
    if not ArmsWelded and Player ~= nil then
        ArmsWelded = true
        LeftShoulder.Part1 = nil
        RightShoulder.Part1 = nil
        RWeld = Instance.new('ManualWeld', RightArm)
        RWeld.Part0 = Head
        RWeld.Part1 = RightArm
        RWeld.C1 = CFrame.new(-0.9, 0.05, -1) * CFrame.Angles(math.rad(-90), math.rad(-16), math.rad(0))
        LWeld = Instance.new('ManualWeld', LeftArm)
        LWeld.Part0 = Head
        LWeld.Part1 = LeftArm
        LWeld.C1 = CFrame.new(0.4, 0.85, -1.1) * CFrame.Angles(math.rad(-90), math.rad(-325), math.rad(5))
        if not HeadWelded then
            HeadWelded = true
            HWeld = Instance.new('ManualWeld', Head)
            HWeld.Part0 = Torso
            HWeld.Part1 = Head
            HWeld.C0 = CFrame.new(0, 1.5, 0)
        end
    end
end

Code for the fake arms:

local function CreateArms()
    if not ArmsCreated and S.FakeArms then
        ArmsCreated = true
        ArmModel = Instance.new('Model', CurrentCam)
        ArmModel.Name = 'FakeArms'
        --Right
        RArm = RightArm:Clone()
        RArm.Material = 'SmoothPlastic'
        RArm.Transparency = S.ArmTransparency
        RArm.BrickColor = S.ArmColor
        local rightMesh = Instance.new('BlockMesh', RArm)
        rightMesh.Scale = Vector3.new(0.65, 0.99, 0.65)
        local rightWeld = Instance.new('ManualWeld', RightArm)
        rightWeld.Part0 = RightArm
        rightWeld.Part1 = RArm
        RArm.Parent = ArmModel
        --Left
        LArm = LeftArm:Clone()
        LArm.Material = 'SmoothPlastic'
        LArm.Transparency = S.ArmTransparency
        LArm.BrickColor = S.ArmColor
        local rightMesh = Instance.new('BlockMesh', LArm)
        rightMesh.Scale = Vector3.new(0.65, 0.99, 0.65)
        local rightWeld = Instance.new('ManualWeld', LeftArm)
        rightWeld.Part0 = LeftArm
        rightWeld.Part1 = LArm
        LArm.Parent = ArmModel
    end
end

Thanks for the help guys. If you have anything you could tell me that might help I would greatly appreciate it.