For your edification from
Your Lesson For The Day
A machine gun is a fully automatic mounted or
portable firearm designed to fire
bullets in rapid succession from an
ammunition belt or
magazine, typically at a rate of 300 rounds per minute or higher. Not all fully automatic firearms are machine guns.
Submachine guns,
rifles,
assault rifles,
shotguns,
pistols or
cannons may be capable of fully automatic fire, but are not designed for sustained fire. As a class of military rapid-fire guns, machine guns are fully automatic weapons designed to be used as support weapons and generally used when attached to a
mount- or fired from the ground on a
bipod or
tripod. Many (but not all) machine guns also use
belt feeding and
open boltoperation, features not normally found on rifles.
By U.S. federal law, a "machine gun" is a legal term for any weapon able to fire more than one shot per trigger pull regardless of caliber, the receiver of any such weapon, any weapon convertible to such a state using normal tools, or any component or part that will modify an existing firearm such that it functions as a "machine gun" such as a drop-in auto
sear.
[1] Civilian possession of such weapons is not prohibited by any Federal law and not illegal in many states, but they must be registered as Title II weapons under the National Firearms Act and have a tax stamp paid. The Hughes Amendment to the Firearm Owners Protection Act of 1986 banned new production of firearms classified as machine guns for most civilian applications, however, so only "grandfathered" weapons produced before this date are legally transferable
In other words the odds of you being anywhere near a person who owns a automatic weapon is about 1 in 100,000 (and even probably higher). The average automatic weapon starts at about $20,000.