Actually, felons can own Blackpowder rifles and revolvers. The law applies only to modern firearms. Blackpowder weapons can still be purchased by mailorder with no paperwork necessary.
A Marine
Sorry, sir; you are mistaken
Sec. 922. - Unlawful acts
and maybe found here
http://www4.law.cornell.edu/uscode/18/922.html (d)
It shall be unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person -
(1)
is under indictment for, or has been convicted in any court of, a crime punishable by imprisonment for a term exceeding one year;
(2)
is a fugitive from justice;
(3)
is an unlawful user of or addicted to any controlled substance (as defined in section 102 of the Controlled Substances Act (21 U.S.C. 802));
(4)
has been adjudicated as a mental defective or has been committed to any mental institution;