.380 Ammo: Who's got it? What's it cost??

Part of production cost is changing over the line to set up for the cartridge to be loaded. That includes the cost of the line being down during the changeover. The entire time the line is down, all the normal expenses continue to accrue, but nothing is being produced that can be sold to recover those expenses.

So the cost of a .380ACP run isn't just the cost of the raw materials, it also includes the cost of having the line down for the changeover to .380ACP as well as the cost of having the line down for the changeover back to 9mm once the run is done.

To know if it really costs more or less to make a run of .380ACP you have to compare the cost incurred in the shutdown and changeover going from 9mm to .380ACP and then a second shutdown and changeover going back to 9mm against the difference in raw material costs.

My guess is that the raw material cost between a round of 9mm and a round of .380ACP is very small. Which means that the changeover/shutdown cost could easily outweigh the small reduction in raw materials costs.