Most of the AR-10 ex-military rifles shipped to the United States were in the form of parts kits, having been previously dismantled, though a few were legally imported as National Firearms Act (NFA) weapons. Large numbers of AR-10 7.62 mm magazines were imported as well. Many of these kit rifles were combined with various semi-auto receivers made by civilian manufacturers in order to permit legal ownership. During the early 1980s, Paragon Sales and Services in Joliet, Illinois manufactured new semi-automatic lower receivers while using imported upper AR-10 receivers originally manufactured by Artillerie-Inrichtingen in the Netherlands.