The U.S. Army, Navy, Air Force, and Marines all refer to the M4 carbine as an “assault rifle.” This class of firearms typically has a feature called “selective-fire” that lets the shooter switch between semi-automatic and fully automatic modes or a three-round burst. Federal law has largely banned civilians from purchasing assault rifles since 1986. “Assault weapons,” on the other hand, is a label often used by the media and gun control activists to describe common semi-automatic rifles used for self-defense and hunting, such as the AR-15. In 1988, a prominent gun control activist wrote that calling these guns “assault weapons” would exploit the “public’s confusion over fully automatic machine guns” and thereby “increase the chance of public support for restrictions on these weapons.” Machine guns are a different class of weapons that commonly feed rounds through a belt (as opposed to a magazine), are secured to a mount like a tripod, and cannot be easily carried around in combat.