Here's the 2ND AMENDMENT:
"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."
Let me put this in easier, "down home", language for you with some historical background...
"Well folks, we just fought this war with England to gain our independance, using a militia. Being that our government is so young and we DO NOT HAVE A BUDGET LARGE ENOUGH TO FUND A REGULAR STANDING ARMY... we're going to pass this amendment to the constitution that says that "ya'll can carry weapons", in case we need to call on you again to defend our young nation."
Whenever NRA and 2nd Amendment supporters quote the 2nd Amendment, such as you, they always seem to ONLY quote the second half of the entire sentence, and ALWAYS fail to mention the first half, which clearly describes the purpose that the 2nd Amendment was intended for.