Thu Oct 08, 2015 3:51 pm
I built one in Konigsberg and had no ammo shortage. The lowest I got to was maybe 1000 - 1300 when I had the heaviest fighting in the summer of 1915, after that, it quickly went up to 2000 or more. Until someone says they had a shortage during fighting, I'd say no need to build more than 1. Of course, make sure your depots are well within range and the ammo will flow where needed.
On second thought, even though I didn't need it in terms of supplying my forces, building one in A/H is probably a good idea, just so they can replace ammo more quickly. The ammo tends to stay in and around Vienna and Budapest.
Only at the very beginning of the game should there be an ammo shortage (due to units not being well-equipped when fighting breaks out). Once that first factory is built, you won't have any more acute problems.