F4U Corsair Ammunition Boxes

There were six ammunition boxes in each wing for the six .50 cal machine guns on the F4U Corsair. On the port wing, 5 of the 6 boxes are marked "1", while one is marked "2". On the starboard wing, 5 boxes are marked "3" while one is marked "4". Can anyone shed any light on why the boxes were numbered this way? I am thinking that boxes 2 and 4 might have carried less ammunition. Does anyone have any pictures or drawings, or possibly an Erection and Maintenance Manual for the F4U that might answer this question?

Thanks.

Ron

I do not know but I will offer two items that might be of use

first as you speculated, different guns had differing amounts of ammo,400 rounds to each of the 4 inner guns, 375 rounds to the 2 outer guns

second, and probaly the real reason, the boxes do not just sit in the wing but rather are loaded with the case lids forming a section of wing skin. Also, the boxes are all of different sizes.

so the numbering system was probably to save time and confusion with the boxes marked "1" and "3" being interchangable with other "1"s and "3"s

This answers your question