This was a quick fix of a possible game-breaking issue.
It seems the game could get saved with no access to ammo, and you could get stuck in a dungeon. While this would be a pretty realistic take on the genre, I decided fun was more important than realism :) and have included some access to a weapon at or near the beginning of each dungeon.
I guess it went unnoticed before, since the game was providing a surplus of ammo. Now that I have made resource management a bit more intensive, this issue became much more apparent.