Just how did you think weapons were shipped around the country from the MNFR to the Military?

That's right, contract Rail, and OTR transport for for materials below certain size/weight.

As ER mentions, the stuff that goes WHISH, ZAP or BOOM! is routed another way, the Electronics/ETC is also not installed.

As for ljk's comment about the umarked truck, of course they are, and have been for years. They are also GPS loc/tracked/ have any number of transponders and some other rather fascinating security measures. The best one is sheer anonomynity.

But they are owned and operated by Civilian Contractors.