Last night I was discussing .44-40 and 45 Long Colt with a friend who knows I have an affinity for cowboy firearms. While I know and can instruct the basics of reloading, he takes reloading to another extreme and even casts his own bullets.
He said he prefers the .44-40 to the 45LC because the thinner brass will expand fuller in the chamber of the rifle on the .44-40. I did some research this morning and found out he was correct (I already figured he was). The brass on 45LC does not seal the chamber as well and can end up fouling the chamber as well as potentially scorch the casing. Best I can find the 45LC (bottom photo) is easier to reload due to the straight casing as opposed to the .44-40 bottleneck casing (first photo below), but with some practice it is not difficult to learn how to handle the .44-40.
On one forum I found a note that the smaller rim on the 45LC can cause issues cycling in a level action, and someone mentioned the bottleneck casing on the .44-40 helps with feeding into the chamber.
So now I’m torn. I guess when I finally decide to go get that Henry or Uberti Henry I’ll probably have to consider the .44-40.