Do some research.
One certainly can own a full auto weapon in the U.S..
Here is my daughter posing (the reason for no safety gear) with a full-auto Uzi she just finished firing.
Do some research of your own. If an automatic weapon was not registered with the ATF as an automatic weapon as of May 19, 1986, it is not eligible for civilian ownership or transfer, thanks to the Hughes Amendment to the Firearm Owner's Protection Act.
Because of the FOPA, a civilian can never own a newly manufactured firearm that fires more than one shot with a single pull of the trigger, which is the legal definition of a machine gun according to 26 U.S.C. 5845(b).
Any full-auto weapons for sale in the United States to civilians, including that fine Uzi your daughter fired, were manufactured and registered prior to May 19, 1986.