In going through my 28mm ACW project, I found some details in the Perry metal packs that I was very impressed with.
Having studied the ACW my entire adult life and also reenacting as a Union soldier with the 14th Conn. and other units for 25 years, my eye caught a few things that some gamers might not be aware of or might not have thought about.
It's clear that Perry did their research homework when sculpting the ACW range.
In the six-figure pack 'Union infantry in frock coats and with knapsacks', there's a few really cool tidbits.
Firstly, the attention to detail in varying the way that soldiers strapped their knapsacks. Look at the guy on the far right. You'll notice that his knapsack cross straps in the front are hooked vertically onto his waistbelt. The rest of the soldiers in the set have them strapped across the chest in the usual "X" shape.
That was indeed an historical alternate way to attach the front straps that took some restriction off the chest and made the knapsack's weight a bit more balanced.
It's cool that this is represented on the model.
When you turn the models around, there's another nice historical tidbit. Some of the soldiers have their knapsacks topped with a roll and others do not. This is representing something that is actually referencing a knapsack regulation and a variant of the regulations and something that even some reenactors are not even aware of despite using the equipment for years.
The straps that were issued with the standard double-bag knapsack were, by the army regulations technically NOT "blanket straps." They were intended to be "greatcoat straps." Again, strictly per the regulations, the soldier's shelter half and wool blanket were meant to be folded and stored inside the knapsack's two interior compartments. The top of the knapsack with the straps was meant to carry the sky blue greatcoat for cold weather. Sometimes the rubber blanket was folded around and rolled up with the greatcoat to make one combined rolled bundle, and both were strapped to the top of the knapsack, which made the entire affair quite top-heavy and unwieldy.
So I decided to portray these men as being straight regulation and carrying their greatcoats as a roll exactly as the regulations specified. Now certainly many soldiers did indeed use the straps to carry the rolled woolen blanket on top so that they could fit other things in the knapsacks, perhaps more personal effects, etc.
The other soldiers in this set of course have apparently ditched their greatcoats altogether and have opted to carry just the shelter half and woolen blanket and get by with that. Now of course, obviously many soldiers ditched the knapsack altogether and opted for the more comfortable blanket roll slung over the shoulder.