Multi-piece frame or receiver.
(d) Multi-piece frame or receiver. The term multi-piece frame or receiver shall mean a frame or receiver that may be disassembled into multiple modular subparts, i.e., standardized units that may be replaced or exchanged. The term shall not include the internal frame of a pistol that is a complete removable chassis that provides housing for the sear or equivalent component, unless the chassis itself may be disassembled. The modular subpart(s) identified in accordance with 478.92 with an importer's or manufacturer's serial number shall be presumed, absent an official determination by the Director or other reliable evidence to the contrary, to be part of the frame or receiver of a weapon or device.