when i was in the military, we went to the rifle range with our m16s, but it was actually a pistol range and people were closer together.
we went thru many firing exercises and the barrels were very hot.
one of the casings from one soldier's rifle flew over and landed on the neck/shoulder of the guy next to him.
he screamed and reached with his left hand to peel it away from his neck while the right hand held onto the weapon.
But the muzzle of the weapon was arching down and the weight caused him to shoot into the concrete pad 3-4 shots.
Concrete chips went everywhere.
Some of the chips hit the guy on either side of him and they thought they were hit with shrapnel for the bullets shattering.
They actually had nicks that were bleeding. \

The casing on the guy's next had rolled below his shirt and clinged to the skin and burned him so bad he had to get medical treatment.

it was a very frightening thing for everyone that was there.
When it happened people were running and diving in every direction.
I was behind the scene about 20 feet waiting my turn.
I would have sworn from what I saw that somebody would have been leaving in a bag.