Add the futures trade in oil. All of the commodity ingredients are transported by diesel powered trucks and trains. Finished products are transported by diesel powered trucks and trains.
It keeps the dairy and potato chip makers decentralized to keep the eventual cost down, for ammo makers, not so much. It takes a certain volume to keep a plant running, if distribution costs go up, you're stuck for it.
A turret press reloading setup costs less than a good scope and will pay for itself in a few thousand rounds. It's not that hard to load decent ammo good enough to match the typical 2MOA fodder dumped on the market, and with a few extra steps, deliver ammo better than the barrel. It's mostly a matter of weighing and measuring, really very little hard work.
If SOME of us spent as much time reloading as chattering on the web, there would be a lot more happy shooters, and threads like this would be meaningless. BUT, myself included, we don't. No real excuse.