You think Piers Morgan would have learned something, anything about rifles, or guns in general since he started basking in the anti-2nd Amendment spotlight. Sadly, no.
Hey Piers, aside from caliber and aesthetics, these two rifles are essentially the same. Neither of them are assault rifles, neither are machine guns, neither is more or less lethal (actually the bottom rifle has a larger caliber, so...). They shoot exactly the same way as each other, at exactly the same rate: 1 pull of the trigger = 1 shot fired and no more.
Obviously, this is already illegal, but I must confess it can be done. Someone with enough determination and wanton disregard for the law can alter just about any semi-auto to become fully auto, if he had the right tools, skills, and knowledge. But a bad guy who does that is not about to be stopped by any gun law you can imagine.