An advanced jig for manufacturing a firearm lower receiver can include an adapter, a guide plate, a front support, a buffer support, a buffer mounting screw and at least one carriage with at least one locating pin. A guide plate can be in a location above the fire control cavity of a lower receiver and can be mounted to the carriage(s) in conjunction with a rotary power tool adapter. The jig can be a universal fitment. The jig can include a bearing to support a rotary tool and can be constructed and arranged to provide for use of at least one guiding feature to facilitate in the guidance of the rotary tool without placing the rotary tool in direct contact with any of a plurality of guidance features for firearm lower receiver manufacturing. A removable locating pin can be situated in a location along the front takedown pin hole of a firearm receiver that is for firearm lower receiver manufacturing.