If shipping is time sensitive be wary of registered mail. I shipped a gun I was returning that way once and it took over two weeks to arrive. I think the owner suspected bad faith on my part.

As someone noted above a registered package must be signed for and put in a locker at each stage of the delivery. My gun showed up somewhere just as the responsible employee went off on a two week vacation.

I instituted a mail search which was fruitless. The gun went into a locker and nobody had any idea where it was until the employee returned to work...Geo