Esoterica

Let's say I have a gun I wanna sell to a friend who lives in another state.

If I am there on a visit can I take the gun to an FFL that's local to him and then do the transfers or do I have to ship it from my place to the FFL?

I wanna be all legal about this, it'd just be handier to do the interstate transfer from hand-carrying it to the FFL than the bother of shipping it.