Try europe first. But remember it's only RIFs, not magazines, not suppressors, not stocks, not rails, not inner barrels or gearboxes, or sights, not even 50% of a RIF, but a whole RIF - though if you haven't a defence ordering a RIF in two parts is not only illegal but could yield negative consequences if caught (obviously does not apply here).
So if you get that evil message from UPS or another courier about airsoft stuff, if theres no RIF in the package, tell them to shuv it (while co-operating fully).