Not sure if anyone saw, but ATF is updating the 4473 again in January. One of the revisions will be to the current question:
"Are you an unlawful user of, or addicted to, marijuana or any depressant, stimulant, narcotic drug, or any other controlled substance?"
New version:
"Are you an unlawful user of, or addicted to, marijuana or any depressant, stimulant, narcotic drug, or any other controlled substance?
Warning: The use or possession of marijuana remains unlawful under Federal law regardless of whether it has been legalized or
decriminalized for medicinal or recreational purposes in the state where you reside."
So, smoke pot, no gun for you!
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Though, it is worth adding that enforcement is so lax with ATF that it probably would never matter, the law is the law and you should follow it.