I've seen the original gear image discussed elsewhere on the internet, and it is an interesting image for the rigger made pouches. The five custom made 5-pocket sections were for one 8-round clip each of caliber-.30 ammunition for the rifle M1. The first section on the left demonstrated the clips were carried perpendicular to the belt. The count would be 25 clips x 8 rounds for 200 rounds of caliber-.30 ammunition, which I suspect would not be as heavy as mentioned with caliber-.45 ammunition, but would be significantly heavier than the 80 rounds carried in the standard 10-pocket ammunition belts, not to mention the extra bulk of the clips although about the same as BAR magazine belts.
The usual combat load for caliber-.30 ammunition was 80 rounds in the belt and two bandoleers totaling 176 rounds, so this trooper was 24 rounds ahead, but it should be considered that ammunition re-supply was a problem for air-landed troops.
The machete suggests that this image was taken in the Pacific area of operations, and some of the extra equipment carried suggests the soldier was a pathfinder, which may account for the extra ammunition carried.