I recently got a copy of the Federal Firearms Regulations Reference Guide. It answers most questions that home builders may have and the price is right as well (freebe). I believe copies maybe requested at: Bureau of Alcohol Tobacco and Firearms, Firarms Programs Division, Washington, D.C. 20226. There is also a book with all revelant state laws too. Becareful as it can cause drowsiness, do not drive or operate machinery.