This would be the pertinent quote you are looking for:
Machine guns are also treated differently. In 1986, as part of
the Firearm Owners' Protection Act (FOPA), Congress prohibited
individuals from owning machine guns, and made it an affirmative
defense that the machine gun was registered before the act took
effect (which was 5/19/86). See 18 U.S.C. sec. 922(o) for the law.
Thus as an individual you can only legally own a machine gun that
was registered before that date. Any registered after that date
can only be owned by SOT's, law enforcement, and government
entities. A SOT may not keep these machine guns after surrendering
his SOT. In order to transfer one of these machine guns, the SOT
must have a request from an agency able to own one for a
demonstration. Or an order from one of those agencies to buy one.
A class 2 SOT can make machine guns for research and development
purposes, or for sale to dealers as samples, or for sale to
government entities. These are commonly called post-86 machine
guns.
As stated above, a civilian may own a machine gun which was registered prior to 05-19-86. The ownership of such weapons is transferrable (subject to all of the registration/tax stipulations), but machine guns which were registered prior to 05-19-86 are VERY pricey. Unless you are very wealthy, owning a machine gun would be a prohibitively expensive undertaking. And as expensive as ammunition has gotten, feeding one would be a rich man's hobby as well. Some of the more exotic machine guns sell for as much as a house, and even the more common ones can rival the cost of an automobile. Supply and demand.
