That's right. "common law" was not 100% exclusive to England which is a "common" asumption to the detractors.
2nd Amendment comes from Vattel’s Law of Nations?
http://books.google.com.ph/books?id=wDOP73CSzicC&pg=PA197&dq=vattel+law+of+nations&hl=en&ei=tF-VTKfKJIWycdeMqaQF&sa=X&oi=book_result&ct=result&resnum=2&ved=0CC8Q6AEwATge#v=onepage&q=vattel%20law%20of%20nations&f=false
see 162.