A few questions - a percussion firearm is considered an antique under US federal law. Is a US export licence required for an exempt firearm? If we are discussing unfinished parts, how is a flintlock barrel distinguished from a percussion barrel? If an antque firearm is exempt from export/import controls, are replacement parts for antique firearms subject to controls? In Canada, is it the percussion barrel, the breechplug, or the assembly of the breechplug and the barrel which is considered to be a receiver, and therefore subject to registration?