There are ammo consumption inconsistencies with weapon modules that use more than 1 ammo per clip.
Reload any weapon module that uses more than 1 ammo per clip, while you have excess crew (more than the minimum/recommended amount) standing by.
Amount of ammo the crew takes from storage should match the set amount in the ammoPerClip setting located in the ModuleType .json file.
Crew takes more ammo than needed for a weapon's reload cycle when crew amount is in excess. This sometimes only happens on the weapon's first reload, but can happen on subsequent reloads. Sometimes crew grabs ammo to resupply a weapon before it's needed/still firing.
Found the bug while modding. Did more testing by changing the in-game rifle to use 2 ammoPerClip.
What ammoPerClip was set at.
The rifle didn't even have to use up its clip and go into a reload cycle before the crew tried to reload it. It just needed a target to be in its arc of fire, and the crew took 2 ammo to reload as soon as the match started.
Using a larger ammo storage with excess crew, more ammo is taken. In the previous example, the crew took the correct amount of ammo despite the gun not needing a reload. In this situation, they're taking 1 more than the set amount.
In this scenario, the crew waited until a reload was necessary, instead of trying to stuff ammo into a chambered weapon.
This might be a good thing, not a bug, if (1) it ensures continuous firing by resetting the weapons ammo, and (2) its controllable, because it depends on having extra crew.
For example I recently made a ship where the ammo is a long way away from the gun.
I was worried that the crew will wait until the gun is empty before fetching more ammo. I am happy to hear the crew will start fetching more before the gun is empty (even if it costs me more ammo).
You have a point. I think that the preemptive ammo-grabbing behavior only manifests when reloading weapons with a greater clip size than 1 (rifles and flak guns for example). I don't have enough knowledge about the game to be sure, but it's possible that this behavior is intended.
But I'm still fairly certain that the way the crew grabs more ammo than needed is bug. I did some more testing with my mod. It's set to use 5 ammo per clip, but the amount taken will either be 10 or 6 while occasionally hitting 5. That doesn't make any sense to me.