This is a demonstration of control of fully automatic weapon fired in overly-long bursts to illustrate control.
George Harris of International Firearms Consultants LLC (http://ifcllc.us) shot the AR-10 and Thompson. The AR-10 was shot with a continuous burst of 20 rounds of 7.62 M-80 Ball. It was a beast to control but was controllable. Harris could put all 20 on a 12″ plate at 25 yards without much trouble.
The other demonstrations are of Jeff Brennan shooting an AK, CZ and RPD running wide open.
The point is, if you know what you are doing, (taught by a trainer that knows and can demonstrate how to shoot full auto) it’s really a piece of cake.
Real world practicality is that you had better have a lot of loaded magazines and several guns available if you are going to do a lot of it. This isn’t a practical approach to effective fully automatic fire, just a demonstration of the control that is possible.