Dems owned the House for many years, had all three seats of power for several years and nothing was put forward regarding anti-gun stuff, why?
We're in an election cycle and this stuff plays well to many on the left and these folks are playing to their base.
With our current Speaker of the House, nothing will get out of the House as long as he's there.
Once the House changes hands, back to the Dems, chances are even then nothing will come of the anti gun stuff because above all else, these people (political class) do not want to have to work a real job.
With all that said, IF congress ever does pass something really stupid like this, the term non compliance comes quickly to mind.
You may find me dead in a ditch one day, but I will be up to my waist in spent rifle brass!