Many years ago, I commanded an Infantry Company (A-4/30 IN) at Fort Sill, Oklahoma. There was only one Infantry battalion on this post, which is the home of the Artillery. We naturally caught all the sh*t details, including prison guard.
The Artillery also had a standard way to deal with problem soldiers -- send 'em to the Infantry. So if you saw a prison work detail on post, the odds were the guards were my men -- and so were many of the prisoners.
One detail was working on the Post Golf Course, which had picturesque stone arched bridges over a meandering creek. One of the prisoners (from my company) said to one of the guards (also from my company), "Hey, man. Would you shoot me if I was to run?"
"Yep."
"Man, I don't believe you."
The guard made no reply, but chambered a round in his riot gun.
"Man, you're just bluffin'. I'm gone."
As the prisoner reached the top of the arch of the nearest stone bridge, going flat out, there was a loud "Boom!"
"I'm shot! I'm shot!"
The guard came up. "Git up. You ain't shot."
"I'm shot! I'm shot!"
Finally, the sergeant in charge of the detail called for an ambulance, and also called me. In the hospital the medics and sergeant told me they had checked the prisoner, and there were no holes in him.
The doctor came out and said, "He's shot -- one pellet hit him."
"But doc, there weren't any holes."
"The pellet utilized an existing hole."
Fire in the hole, indeed -- and that's exactly what might happen if someone dropped a capped and loaded cylinder.