And the doubters will always bring up the 2nd Amendment, but never mention it begins with "well regulated".
The definition of "regulate" back when the Constitution was written is not what you believe it to be. Your use implies that you believe it meant to limit via legislation. In fact, the definition back then was the exact opposite. Just as Metamucil helps to keep your body regular, the term to regulate meant to make regular.
Judge Andrew Napolitano has discussed this issue several times in the past few years in regards to the meaning of the phrase "to regulate" when the founders wrote the commerce clause. It's the same thing with its use in the 2nd amendment.