BATF. I wasn't aware of the change in 2009 (maybe it was always there, but I didn't know). You can now take your suppressors or AOW's to any state where they are legal without notifying the bureau. I'm pretty sure they want you to tell them when you move permanently.


Form 5320.20, Application to Transport Interstate or to
Temporarily Export Certain NFA Firearms
The GCA, 18 U.S.C. 922 (a)(4), requires that a person
obtain permission from ATF to transport a machinegun,
short-barreled rifle, short-barreled shotgun, or destructive
device across State lines. Regulation 27 CFR 478.28 exempts
an FFL who can deal, import, or manufacture firearms and
who has paid the applicable SOT based on this[?] requirement
and also exempts a person licensed as a collector of
curios or relics if the firearm being transported is a curio or
relic. Note that there is no requirement for any person to
receive permission to move a silencer or firearm classified as
an “any other weapon” across State lines. The NFA Branch
will also accept an ATF Form 5320.20 to notify the NFA
Branch of an intrastate change of address.

Edit: http://www.atf.gov/files/publication...er-2009-11.pdf

Go to the section titled "Form 5320.20, Application to Transport Interstate or to Temporarily Export Certain NFA Firearms" on page 6).