ORIGINAL SOURCE

Years after the battle [Battle of the Little Bighorn] a number of Indians claimed that the soldiers became so terrified they dropped their guns. In fact, quite a few did drop their guns or throw them aside, although not necessarily in panic. The guns occasionally jammed because the soft copper shells—unlike hard brass—could be deformed by exploding powder, causing them to stick in the breech. Furthermore, troopers often carried loose ammunition in saddlebags where it was easily damaged. Another possible reason turned up when one of [Major] Reno’s men talked with an ordnance officer. This officer subsequently wrote to the Chief of Ordnance that Custer’s troops used ammunition belts made from scrap leather. The copper shells “thus had become covered with a coating of verdigris and extraneous matter, which had made it difficult to even put them in the chamber before the gun had been discharged at all. Upon discharge the verdigris and extraneous matter formed a cement which held the sides of the cartridge in place against the action of the ejector. . . . ”

Whatever the cause, it could take some time to pry a deformed shell out of the breech, or one that had been cemented in place, which explains why troopers under attack occasionally threw aside their rifles. To the Indians it must have appeared that a soldier who did this was terrified—as of course he might have been—but at the same time he might have been enraged.

From Connell, Evan S. Son of the Morning Star: Custer and the Little Bighorn. San Francisco: North Point Press, 1984.

[The source passage is from pages 306-7.]