The next step was to select the setions that will be used for the receiver and those for fillers. The parts were blasted to remove all the crud and the center section was cut and milled square.
This section needs to have some areas where the full auto sear parts go filled in to make it legal. This is the area shown in the white box, a bolt block needs to extend into the bolt sear slot inside. This needs to be done BEFORE any other work is done.