First, the right to defend oneself against unjustified assault is a human right. The Second Amendment prohibits the government from denying Americans their human rights.
And their is no "Second Amendment right". The right is inalienable. The 2nd doesn't grant any rights, it prohibits the government from denying Americans their rights understood to be inalienable. This right existed before the Constitution, it exist now and it will exist after the Constitution.