Canyon- CA has a requirement that any FFL Dealer shipping TO a CA FFL Dealer must register with the CA DOJ. Many dealers in other states just will not do that.
When ownership is being transferred across a state line, it must come TO a FFL holder in your home state, Does NOT have to come FROM a FFL. While some dealers will not, a FFL can RECEIVE a firearm from anyone- they DO need ID on the sender so they can log it in to their bound book.
If you go to gunbroker.com, there is a "find a FFL" function. These are dealers that have registered with gunbroker as being willing to serve as a transfer FFL. Put in your zip code, will pull up folks in that area. MOST list their charges.