brass jackets and collars
When I was in the Army in the early sixties my basic training company was charged with pulling targets for civilian M1 rifle competetion. We used the typical canterlevered sash targets
If we were too busy we could not strip the targets and after 7 + targets were pasted on one another some of the brass jackets would strip off the cores and drop into the pits.
I was on more than one occasion that one of these jackets would land in someones shirt collar. Initially the trainee would think he was shot.