Unlocked military recipes for turrets and bullets. But bullets take gunpowder, which takes sulphur? Sulpher takes automation science, py science 1, plus logistics science, which is literally 40 tech tree levels away.

Am I missing some other way of making bullets, or gunpowder, or sulphur? Or is this a true bug?

You should be able to make sulfur from something that comes from Tar.

Please use mod like https://mods.factorio.com/mod/what-is-it-really-used-for or Helmod to easier identify what you can use to make something.

Assuming this is a bug, could maybe either the gunpowder recipe be changed to use coal dust, or could ash separation produce a little sulphur?

domisPL, thanks for the quick reply. I'm using FNEI and searching for anything that produces sulphur. All sulphur producing technologies are currently still out of reach (I've almost finished all the automation science researches). I do see that tar can produce aromatics, which can later produce sulphur, but that's not unlocked until the logistics science's sulphur tech. I'm not seeing anything else in tar processing that leads to sulphur (at my tech level).

Using the mod https://mods.factorio.com/mod/what-is-it-really-used-for im able to see recipe for Gunpowder and then go up the tree of ingredients like this:

gunpowder <- sulfur <- acid gas <- tailings <- tar (tar quenching recipe)

Sulfur from Acid Gas takes Evaporation Processing 1 research, which takes Py Science 1 (red vial), which isn't available to me yet. I've unlocked Py Science 1, but I'm a long way from having the infrastructure to make it.

Acid Gas from Tailings also takes Evaporation Processing 1 research, same as above.

Tailings from Tar takes Tar Queching research, which I have.

I'm nowhere near being able to do Py Science 1 yet. So while this is better news than I started with, the bug report stands: bullets can't be made until long after they are "unlocked".