Post-ban receivers have a circle milled into the side of the magwell. They were originally bead-blasted to a non-glare finish. All others are pre-ban. (This is unverified info…) Also, they used to be NESARD. Rumored to have been owned by Dick Drasen (currently M&A Parts) and produced lowers only out of Barrington, Illinois. No complete guns were sold (again, unverified info).