A registered possessor of an NFA firearm, other than an FFL/SOT, may not lawfully transport in interstate or foreign commerce any destructive device, machinegun, short-barreled shotgun, or short-barreled rifle, without prior written approval of ATF, specifically the NFA Branch. Approval for the transportation may be obtained by either a written request, or an approved application filed with ATF on Form 5320.20, Application to Transport Interstate or to Temporarily Export Certain NFA Firearms. Please note that applications to transport NFA firearms will be approved only if consistent with all State and local laws.
[18 U.S.C. § 922(a)(4); 27 C.F.R. § 478.28]