The stress thing is spot on.
I remember a programe about the American Civil War.
Someone who excavated one of the big battlefields said they quite often found Confederate muzzle-loader muskets that that been loaded three or four times on top of each other by nervous soldiers.
When the Union soldiers started using magazine-fed rifles which (in the words of the rebels…“They could load on Sunday and fight with all week”) the nerves can only have got worse.