I always believed the right to bear arms is not a right granted by the government or the constitution, but only protected by it.
The declaration of independence states:
"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. - That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, - That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.
We get our rights from our creator. Protecting our life and liberty is a right we all already have irregardless of the constitution. The constitution does nothing else but say the government shall not infringe upon that right given by God.
"the right of the people to keep and bear Arms, shall not be infringed"
I think the reason they placed this right behind free speech, is because of how important it is to our liberty.
It helps guarantee as a people our ability to enact the second bold statement in the decleration of independence if needed.
The second amendment essentially helps guarantee our other rights will not be removed by the government.