27 C.F.R. § 479.82
Transfer tax rate
(a) The transfer tax imposed with respect to NFA firearms transferred within the United States is at the rate of—
(1) $200 for each firearm transferred, in the case of a machine gun or a destructive device; and
(2) $0 for any firearm transferred that is not described in paragraph (a)(1) of this section.
(b) The transferor must pay the transfer tax.