I not sure this purported program could include the homeless, for per the infamous Form 4473 (https://www.atf.gov/file/61446/download https://www.atf.gov/file/6

I not sure this purported program could include the homeless, for per the infamous Form 4473 (https://www.atf.gov/file/61446/download https://www.atf.gov/file/61446/download has a 2012 version), you've got to supply your "Current Resident Address", which cannot be a P.O. Box. Which doesn't forbid possession, or legal purchase by private sale, just maybe doing it through an FFL as the mechanism necessarily is detailed in the web site.