At what point will Federal Firearms Licensees know that a firearm that they have not received is in fact lost? In other words, when does the 48-hour clock start?
Most FFLs seem to use USPS for shipping firearms - because they can and because it is far less expensive than UPS/FedEx. USPS has a long tradition of having letters and packages sit for literally decades before being delivered - and usually without any explanation of why or any apology for the delay. So if USPS has the package and just has not gotten around to delivering it yet, can you really say the firearm is lost?