Bill and George are right but I would have both your name and the FFL on the ins. It should be technically his until it arrives but why take a chance. If it is off his books is the ins valid? Almost certainly. But leave no loophole for the ins co to twist out of in case of a claim.

I've run into this several times. It comes down to one of three things. The other FFL does not know the law. The other FFL thinks that he is doing the shipping FFL a solid by making you pay him to ship the gun. Or third he hates non FFL sellers and likes to be a jerk. Some FFL think you can not receive your own long gun back in case of a return. I've done it dozens of times but still run into the uninformed about twice a year.