Supplies, Tonnage, and what gets there

During the 20th Century logistics people for the military (all sides) always talk about tonnage of supplies needed to get to a unit (usually a division) on a daily, weekly, monthly basis but I have never seen any study on the relationship of shipped tonnage to actual effective supplies that got delivered.  How much packing material weight is there compared to shells? One reason the modern US military went to 5.56 (.223 cal) M16s was that smaller rounds equated to more carried per person.  Of course they waste more rounds due to auto setting (now fixed 3 round bursts in the M16-A2 model from what I have read). 1000 rounds of WW II ammo rifle type ammo weights around 70 lbs in the shipping crate, I would expect the 5.56 mm to come in with 2000 rounds at the same weight.  An American division could go through 45,000 rifle rounds in a days combat - a ton of rifle ammo. However, say seeing a statement that a WWII division needs 50 tons of supplies a day does show you how many trucks are needed to move it to them (20 2.5 ton trucks), but not what really is being used. fuel weights around 6 1/2 lbs a gallon so using up 3000 gallons of fuel a day would be ~19500 lbs = 9.75 tons of supplies just for fuel. Leaving 10.25 tons for everything else. The only way to figure this out is look at the original supply documents per day and find original weights of items shipped in the crate and the weight of each item just before use to see what the percentage of packing really was.