Your warehouse picture may be a closer analogy than some might think.
Consider that not all ammo is US made.
Consider that a great deal of it is imported.
Consider that the ammo to be imported is in containers on docks.
Consider who controls the docks.
You’re so right. I hadn’t thought of tat angle.
I was at a local FFL getting some CTC Red Laser Grips fitted to 2 Kimber 1911 .45s yesterday, and all the ammo cases of 7.62x51/.308 and .45 were Prvi Partizan from Serbia. He said he can’t get US-made ammo very readily, anymore. $999/1,000-rnds. Wow.
So glad I kept stocking-up since 2001 and have a formidable inventory, now, for 7 calibers and 1 ga.