Licensed dealers can use USPS. I do it all the time.I guess I was under the mistaken impression that you could not ship guns via USPS, that you had to use UPS or FEDEX like I have done in the past. One of my officers sent his duty weapon to Glock back in the late 90's via UPS. The box arrived at Glock void of the pistol. UPS and BATF discovered the employee stealing the guns on the way to Glock. Imagine that employee theft.