If we raise the age to buy a firearm, we should also raise the age to vote. If you're not responsible enough for 1 Constitutional Right, you're not responsible enough for the other. Then, logically, we should also raise the age to buy tobacco, consent or get married. Because clearly they're not mature enough to make those kinds of decisions for themselves. And lastly, the age of enlistment/selective service should be raised. How can we send people to war who are not responsible enough to participate in their own government?