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.
Think about the people who wrote and passed this amendment. The original intent of this was to keep the people safe not from crime, but from their own government. They had just fought a war to free themselves from the tyranny of their own leaders.
It may seem a little extreme, but I take this to mean to not ban any type of weapon. If the government/military can legally own it, the private citizen should be able to legally own it.
Our founding fathers would not want us to be under-powered when our government becomes corrupt enough to come down on it's people.