To illustrate how stuff might get moved around in USA - different than I know about in Canada. I ordered some "A-ZOOM 17 HMR 6 pack dummy rounds" on Amazon.ca, last Saturday (June 11) - turns out the seller is in Lufkin, Texas - parcel had gone to Shreveport, Louisiana, and now is in Illinois - this is per the USPS tracking function - the parcel has a USPS tracking number, but USPS has not yet "received" it - has been moving by something called "GlobalPost", which I presume is a courier.
UPDATE: June 25 - item is still in Illinois - now at a GlobalPost centre 14 miles away from first one - is still not "received" by USPS. For those that care, does not appear that Canada Post has a monopoly on parcels sitting and not going anywhere ...
Because USPS has not "received" it, I presume is why that USPS tracking number does not show up on Canada Post tracking, but it does show on USPS tracking - as not being received by them yet, but showing all the places that the parcel went with their "partner" - GlobalPost. Since June 16, the parcel has been at Carol Stream, Illinois, now is in Itasca, Illinois (June 25) - waiting to be "received" by USPS, to then be moved on to Canada, I presume.
So, the parcel appears to have moved about 950 miles, if it went in a straight line, which it did not, within USA, by courier, to get to USPS, then has another 1,050 miles to get to me, if it moves in a more or less straight line - which it will not, no doubt about that ... And, somewhere, has to clear through Canadian Customs before I get it. To be noted - that parcel is not "late" - as per Amazon.ca, is due here by July 5.