The National Rifle Association believes it is our constitutional right to bear arms, any kind of arms.
When the Second Amendment was written - "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" - the patriots who fought in the revolution were expected to fight again if called upon. The Second Amendment was pertaining to that provision.
Rifles were single-shot ball ammunition, not automatic and semi-automatic assault weapons capable of firing hundreds of rounds in minutes. There's no reason why average Americans need or should have anything more than a simple hunting rifle or a revolver.
One quip anti-gun control enthusiasts like to spurt - "Guns don't kill people, people kill people" - may be true literally, but if we compare a revolver and an AK-47, giving each one minute of constant firing, how many possible kill shots would each get? Any reasonably intelligent person could surmise through common sense that the AK-47 would highly increase the kill factor. The revolver would have to be reloaded several times, making it easier to stop a person from getting off more shots.
Conservatives claim liberals want to take all guns from gun owners, trampling their liberties. Not true. Background checks, waiting periods and restrictions on felons and the mentally ill are meant to keep firearms out of unstable hands. Have your guns if you pass the requirements.