Before 2008, your right to bear arms was not Constitutional per se. It was statutory. As in, it existed, but not because of the Constitution. It was no more Constitutionally protected than your right to drive a car.
District of Columbia versus Heller was the first Supreme Court case to address the existence of an individual right to bear arms. There is no case law confirming or denying its existence before then. Pointing directly to the Second Amendment doesn't work because the Second Amendment grants the right to keep and bear arms to "The People" because "A well regulated militia" is "necessary to the security of a free state."
The grammar of that Amendment, by the way, is an issue... because it's different in the text that Congress passed than it is in the copies that the States got and ratified.
As passed by Congress:
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
I don't like that one. The first and last commas just doesn't make grammatical sense.
As ratified by the States and authenticated by Thomas Jefferson:
"A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed."
Makes a lot more sense, doesn't it? It reads like a grant of authority to the States to raise well-regulated militias. It's a power delegated from the "United States" to the States. It's the version that the States passed. And its language certainly implies that the individual States, not the federal government, and hopefully not the Supreme Court, get the say-so on future changes to "the right of the people to keep and bear arms," seeing as how this Amendment exists to address the issue of "the security of a free state."
So then we get the Miller decision in 1939, in which the Court says that
"In the absence of any evidence tending to show that possession or use of a 'shotgun having a barrel of less than eighteen inches in length' at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument."
Which is SCOTUS for "The Second Amendment doesn't apply to this case."
Every time the Court addressed a Second Amendment issue thereafter until 2008, it cited Miller and did the same thing the Court did in Miller for the same reason: if you're not part of a well-regulated militia, the Second Amendment does not protect any right to bear arms you may think you have.
And, by extension, any right to bear arms you may have is statutory.
Heller treads on VERY new ground. The Scalia decision even admits it. "since this case represents this Court’s first in-depth examination of the Second Amendment, one should not expect it to clarify the entire field."
Seriously, read the Heller decision. And definitely read the dissents.
http://www.law.cornell.edu/supct/html/07-290.ZS.html