How was it shipped KY Jon ? Priority ? Have you-or the seller tried going directly to the USPS to see if they can track it on their system-I have had better success with that.
I have had no issues shipping firearms USPS( and declaring them)-I have had several issues with firearms shipped to me from FeEx ,I will not use UPS as I have known several instances of non payment of insurance .
As far as declaring there is a firearm with USPS (you must with UPS- Fed Ex),its not clear.
To ship a hand gun USPS you must tell them its a hand gun and sign a 1508 form-and
must be a manufacturer or "bona fide dealer"https://about.usps.com/forms/ps1508.pdfHowever USPS
For those unlicensed long guns can go USPS-and there does not seem to be a requirement that you declare its a gun.
https://www.atf.gov/content/firearms-frequently-asked-questions-unlicensed-persons: May a nonlicensee ship a firearm through the U.S. Postal Service?
A nonlicensee may not transfer a firearm to a non-licensed resident of another State.
A nonlicensee may mail a shotgun or rifle to a resident of his or her own State or to a licensee in any State. The Postal Service recommends that long guns be sent by registered mail and that no marking of any kind which would indicate the nature of the contents be placed on the outside of any parcel containing firearms. Handguns are not mailable. A common or contract carrier must be used to ship a handgun.
[18 U.S.C. 1715, 922(a)(3), 922(a)(5) and 922 (a)(2)(A)]
For unlicensed-handguns must go common carrier
and all firearms must be declared : : May a nonlicensee ship a firearm by common or contract carrier?
A nonlicensee may ship a firearm by a common or contract carrier to a resident of his or her own State or to a licensee in any State. A common or contract carrier must be used to ship a handgun.
In addition, Federal law requires that the carrier be notified that the shipment contains a firearm and prohibits common or contract carriers from requiring or causing any label to be placed on any package indicating that it contains a firearm. [18 U.S.C. 922(a)(2)(A), 922(a) (3), 922(a)(5) and 922(e), 27 CFR 478.31 and 478.30]