18 U.S.C. 922(o), also known as the Hughes Amendment, is a violation of the 2nd amendment. This law has created a price increase of transferable machine guns to climb %2000 effectively making it unfeasible for a regular law abiding citizen to purchase one. With the ATF not processing any Tax Stamps for new machine guns, and transferable guns dwindling and priced out of the hands of ordinary citizens, this law has in affect become and outright ban.
It is unlawful per the 2nd amendment of the constitution to ban the purchase of any weapon from private citizens. A ban is one of the most direct methods of infringement.