Our Bill of Rights does not grant rights, it preserves and guarantees
pre-existing individual rights. How do we know this? The Ninth
Amendment states:

“The enumeration in the Constitution, of certain rights, shall not
be construed to deny or disparage others retained by the people.”

In other words, we have other rights beyond what is expressly stated
in the Constitution, and the federal government is not justified in
denying us those rights.

http://www.guncite.com/onething.html

What could those rights be? Although, this Web site is not for the
purpose of discussing natural and positive rights, below are quotes
from two Founding Fathers telling us that the right to self-defense
is a natural right, it cannot be justifiably taken away by any
governing body.

“I go farther; and now proceed to show, that in peculiar instances,
in which those rights can receive neither protection nor reparation
from civil government, they are, notwithstanding its institution,
entitled still to that defence, and to those methods of recovery,
which are justified and demanded in a state of nature.”

“The defence of one’s self, justly called the primary law of nature,
is not, nor can it be abrogated by any regulation of municipal law.”
— James Wilson, Wilson, Of the Natural Rights of Individuals, in
2 The Works of James Wilson 335 (J.D. Andrews ed. 1896).

The above quote is from a series of lectures given between 1790 and
1792.