The full semi-auto ban will never happen, you're correct. The genie is out of the bottle on that one. The country is too big, has too many wide-open spaces, and too many semi-autos already sold. The reaction to the ATF showing up on some otherwise law-abiding hick's doorstep to collect his semi-automatic weapons, just like the NRA bleated at him for years that (((They))) would, is going to be very, very ugly. The NRA would jizz themselves hastening to canonize the "great patriots who stood their ground", or whatever. This would very likely trigger a guerrilla version of Civil War 2.
The problem is, the NRA and their paid-for lackeys in Congress won't give even a single inch on any of the less severe proposals that a vast majority of Americans agree with, such as what has already been discussed here ad nauseam.
There's the rub.