DDTC has a program called International Trade in Arms Regulation (ITAR). We need to learn more about it because it will and has already started putting some firearm parts manufacturers out of business with the extremelly high tax. You not only have to deal with BATF but now also the State Department. STI products in 3 years went from paying $750 dollars per year to $18,000 dollars per year without notification. Don't pay the tax you are immediately closed and face federal prosecution. This will crush small business firearm parts manufacturers.
For example if you cast bullets and sell them to your neighbor you have to register you need to file with the DDTC.
Under subsection 1(a) of the ITAR includes all firearms, barrels, "military" scopes, components, parts, accessories and attachments (C-more sites and even moon clips for revolvers qualify)
Subsection III includes manufacturers of ammunition, bullets, and technical data for the production of the above also have to register.
http://www.pmddtc.state.gov/regulations ... icial.html