Looks like the administration is trying to go after NFA gun trusts:
http://thehill.com/blogs/regwatch/pending-regs/318133-white-house-reviewing-draft-gun-control-rule
The Obama administration is working to close a loophole in the nation’s gun laws that allows for some machine guns and sawed-off shotguns to be sold without the buyer submitting fingerprints or photographs.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is working on a new regulation that would require more background information when the weapons are sold to someone through a corporation or legal trust.
http://thehill.com/blogs/regwatch/pending-regs/318133-white-house-reviewing-draft-gun-control-rule