weird bug whenever i reload my gun?

https://www.youtube.com/watch?v=f4wZ5Lvbw28&feature=youtu.be

Shooting script:

while wait() do
    if mouseDown then
if Ammo>0 and not Reloading then
  Ammo=Ammo-1
    local gunfire = script.Parent:FindFirstChild("Gunfire")
    gunfire:Play()
    RecoilAnimation:Play()
    wait(0.1)
    script.Parent.FireEvent:FireServer(Mouse.Target.Parent, script.Parent:FindFirstChild("Damage").Value)
    elseif Ammo == 0 and not Reloading then
    local EmptyClip = script.Parent:FindFirstChild("EmptyClip")
    EmptyClip:Play()
    wait(0.4)
    else

    end
end