Just so we are all clear, here is the language of the law (18 USC 922(z)):
(z)Secure Gun Storage or Safety Device.—(1)In general.—Except as provided under paragraph (2), it shall be unlawful for any licensed importer, licensed manufacturer, or licensed dealer to sell, deliver, or transfer any handgun to any person other than any person licensed under this chapter, unless the transferee is provided with a secure gun storage or safety device (as defined in section 921(a)(34)) for that handgun.
(2)Exceptions.—Paragraph (1) shall not apply to—(A)(i)the manufacture for, transfer to, or possession by, the United States, a department or agency of the United States, a State, or a department, agency, or political subdivision of a State, of a handgun; or
(ii)the transfer to, or possession by, a law enforcement officer employed by an entity referred to in clause (i) of a handgun for law enforcement purposes (whether on or off duty); or
(B)the transfer to, or possession by, a rail police officer directly employed by or contracted by a rail carrier and certified or commissioned as a police officer under the laws of a State of a handgun for purposes of law enforcement (whether on or off duty);
(C)the transfer to any person of a handgun listed as a curio or relic by the Secretary pursuant to section 921(a)(13); or
(D)the transfer to any person of a handgun for which a secure gun storage or safety device is temporarily unavailable for the reasons described in the exceptions stated in section 923(e), if the licensed manufacturer, licensed importer, or licensed dealer delivers to the transferee within 10 calendar days from the date of the delivery of the handgun to the transferee a secure gun storage or safety device for the handgun.
I get that some FFL's and some ATF agents will interpret it how they like. But this is what a court will use to make determinations if it ever becomes an issue. (And yes, I think the law is crap).