No, its not a red herring or anything fishy at all. U guys slay me.
This ain't a Rubic's Cube exactly. Because of their size and shape only seven boxes of 25 rounds fit into a .50 cal can and there is room to spare -- just not for another full box of 25. The smaller individual size of five-round boxes means that they can be arranged in more variation and more should fit in.
Loose, there'd be even MORE variation and less airspace taken up.
SOMEONE must have actually done this!?