Taken from this thread. Credit to @Zbrochuッ
On one of the dev servers, the Abrams ammo rack was changed to having a 3 round rack at the gunners feet. The order of ammo feed was also changed.
The problem is, it makes no sense, and from what I could find, the 3 round rack there was removed due to issues with safety - it defeats the entire purpose of having the bustle blowout panels.
This was already brought up once before, with the 105mm Abrams, although that time the rack labeled “3” was actually erroneously the first stage ammo stowage, which is not the case here.
Logically, it makes no sense for the 3 round extra stowage to be filled before the bustle, or even before the floor ammorack. If it is to stay, I suggest making it the last stowage to fill, after the 8-round compartment in the hull, which itself should be after the rounds in the bustle.