I've lurked this forum for a few years and finally joined. Sorry if this is covered in another thread, and if so post a link and delete this thread. Looking to build an AR pistol, however uncertain of a few rules and regulations. If a stripped lower is sold in a private sale, is it considered a rifle, lower, or other? I don't want to buy a lower that is thought of as a rifle receiver by authorities, and build a pistol, that because of crazy laws, says that receiver was originally marked as a rifle lower and therefore I just built an illegal SBR. Any input is appreciated.