....(g) It shall be unlawful for any person-- ....(5) who, being an alien-- (A) is illegally or unlawfully in the United States; or (B) except as provided in subsection (y)(2), has been admitted to the United States under a nonimmigrant visa (as that term is defined in section 101(a)(26) of the Immigration and Nationality Act (8 U.S.C. 1101(a)(26))); .... to ship or transport in interstate or foreign commerce, or possess in or affecting commerce, any firearm or ammunition; or to receive any firearm or ammunition which has been shipped or transported in interstate or foreign commerce.....
[ blah, blah, blah, yada, yada, yada] ....
(y) Provisions relating to aliens admitted under nonimmigrant visas.--
(1) Definitions.--In this subsection--
(A) the term “alien” has the same meaning as in section 101(a)(3) of the Immigration and Nationality Act (8 U.S.C. 1101(a)(3)); and
(B) the term “nonimmigrant visa” has the same meaning as in section 101(a)(26) of the Immigration and Nationality Act (8 U.S.C. 1101(a)(26)).
(2) Exceptions.--Subsections (d)(5)(B), (g)(5)(B), and (s)(3)(B)(v)(II) do not apply to any alien who has been lawfully admitted to the United States under a nonimmigrant visa, if that alien is--
(A) admitted to the United States for lawful hunting or sporting purposes or is in possession of a hunting license or permit lawfully issued in the United States;
(B) an official representative of a foreign government who is--
(i) accredited to the United States Government or the Government's mission to an international organization having its headquarters in the United States; or
(ii) en route to or from another country to which that alien is accredited;
(C) an official of a foreign government or a distinguished foreign visitor who has been so designated by the Department of State; or
(D) a foreign law enforcement officer of a friendly foreign government entering the United States on official law enforcement business.....
18 U.S.C.A. § 922 (West)