Holder is not talking about "assault weapons' or machineguns. He is talking about those Mosin-Nagant rifles, Nagant revolvers, P1 pistols, and Yugo Mausers folks have been buying for years.
GCA '68 banned the importation of milsurp firearms, supposedly to prevent another president from being assassinated with an evil Carcano. The fact was that a good part of the law was written by Winchester's lawyers and intended to prevent competition from milsurp rifles. Winchester, based in New Haven, publicly opposed Sen. Tom Dodd (D-CT), the main sponsor of the bill, but secretly donated tens of thousands of dollars to his campaign.
In 1986, Congress kept the milsurp ban but was persuaded by gun collectors and the NRA-ILA to add Paragraph 925 (e), which reads:
(e)Notwithstanding any other provision of this title, the Attorney General shall authorize the importation of, by any licensed importer, the following:
(1)All rifles and shotguns listed as curios or relics by the Attorney General pursuant to section 921(a)(13), and
(2)All handguns, listed as curios or relics by the Attorney General pursuant to section 921(a)(13), provided that such handguns are generally recognized as particularly suitable for or readily adaptable to sporting purposes."
The word shall makes issuance mandatory, but the law leaves it up to the AG to decide what guns are C&R, so it is pretty obvious that Holder will just ban all or almost all milsurp imports.