^This^Check out a service called," ship my gun".
I've used them with complete satisfaction and they were the cheapest, FOR A HANDGUN. For long guns,USPS is legal,as long as you ship To an FFL.
I've used them about 10 times in the past year or 2 and the prices are about half and ease of use is excellent. This is Buds service so you get their buying power/volume discount on shipping.