Well, you certainly can go through a dealer on your end to ship for you but I wonder why would you take the extra step and suffer the added expense of going through a dealer on your end to ship rifles to a dealer with an FFL who is in another state? You legally can ship legal (on a federal & state level) rifles & shotguns directly to an eligible FFL holder either via UPS or the USPS. Just make sure the FFL is legitimate (here), that the rifles & shotguns you plan to ship are legal to own in that other state and can be shipped to an FFL holder under that state's laws and that any magazines you ship are also legal in whatever state. Do not expect a dealer with an FFL to necessarily be knowledgeable of the laws of those other states. In my experience, many do not have a clue to those state laws nor even to many federal regulations concerning shipping and receiving firearms. If you have any concerns, the ATF website spells most of it out and in addition, I always have found them to be helpful when I have made inquiries about the legality of transferring/shipping firearms; well not always but almost always. There is one exception that comes to mind when I spoke to a truly anti-RKBA arsehat at ATF. All the other times though, and there have been several, ATF reps have been very polite and informative. I prefer to email them and thus get answers in wring but have also spoken to them on the phone.
It is also illegal to usps. Or at least it was yrs ago
You can ship long guns via usps. Dealers can ship handguns and long guns via postal service. Shipping a long gun via USPS is an exercise in futility. They are almost always more expensive that FedEx/UPS and their antiquated tracking system sucks. Dealers like to ship handguns through USPS because of the flat rate shipping instead of having to ship overnight.
