Buy throwaway phone and a 30 round magazine - pay cash.
Load magazine, and stick the magazine in the AR and ship it common carrier and undeclared, to the SOB, signature confirmation, pay cash, no return address.
Monitor shipment. When it's close to delivery, call local LE with throwaway phone. Tell em a local is receiving an un"SAFE" firearm, w/o a FFL. Give em tracking # and delivery address and date.
