It all depends on what the contract says.  The following FAR references provide guidance for establishing contract terms based upon FOB origin or destination:  FAR 47.303, FAR 47.304-1, FAR 47.305-1, FAR 52.247-45, FAR 52.247-46, FAR 52.247-47, FAR 52.247-49, FAR 52.247-50, and FAR 52.247-51.   

The definition of “FOB,” per FAR 2.101.  The term free on board (FOB) is used in conjunction with a physical point to determine:

•            The responsibility and basis for payment of freight charges; and

•            Unless otherwise agreed to, the point at which title for goods passes to the buyer or consignee.

For example, contracts with "FOB origin" generally require the Government to pick up the deliverable at the contractor's warehouse, with the Government responsible for shipping costs from the warehouse.  In contrast, "FOB destination" contracts generally requires the contractor -- at the contractor's expense -- to ship the contract item to a Government loading dock. Usually, the FOB point is either the place of shipment origin or final shipment destination but it can be anywhere in between. For example, the FOB point could be an airport or dock where the shipment will be consolidated with other items for transport to a final destination.

It's also important to read the inspection clause in the contract.  For example, according to FAR 52.246-2 -- Inspection of Supplies-Fixed-Price – paragraph (c) “the Government has the right to inspect and test all supplies called for by the contract, to the extent practicable, at all places and times, including the period of manufacture, and in any event before acceptance. The Government shall perform inspections and tests in a manner that will not unduly delay the work. The Government assumes no contractual obligation to perform any inspection and test for the benefit of the Contractor unless specifically set forth elsewhere in this contract.”   Additionally, in paragraph (j), “the Government shall accept or reject supplies as promptly as practicable after delivery, unless otherwise provided in the contract. Government failure to inspect and accept or reject the supplies shall not relieve the Contractor from responsibility, nor impose liability on the Government, for nonconforming supplies.

Bottom line: Read the contract!   If the contract terms state FOB origin, then acceptance generally occurs at place of performance.  Also, read the Inspection Clause as well as the other inspection/acceptance terms found in Section E – Inspection and Acceptance – of the contract.  The contract terms and conditions govern the rights and responsibilities of the parties, but in some limited circumstances, the Contracting Officer can make an in-scope change to the contract under the authority of the Changes Clause.  For example, the “place of delivery” can be changed according to FAR 52.243-1 assuming the contract is fixed price.  Once again, you need to read appropriate clauses in the contract.  However, other than the “place of delivery” or “place of performance”, be careful when considering a change to the inspection and acceptance terms and conditions in the contract.  For example, the Inspection Clause normally cannot be changed except in rare circumstances.   The Contracting Officer would probably need to write a scope determination which would need to be reviewed by legal and the change to the contract would need to be mutually agreed to by the parties.  Finally, I would strongly recommend discussing any changes to the inspection/acceptance terms and conditions with the Contracting Officer and most importantly legal counsel.