Without barrel or chamber, lots of unburned powder.
I remember seeing something like this but they used a 12ga flare pistol with duct tape re-enforcing the barrel. Don’t recall if it blew up or stayed together but I know I would not want to be the one holding it when the hammer dropped.
When I was a teen, me and my friends used to remove the shot from shotshells, tape a BB to the primer and throw them into the air where they’d land on the street, base down. The BB acted as a firing pin, igniting the primer and powder charge.
we did the same only with a marble. only on the 4th of July of course;)
Never mind…
Lol, I don’t know what you wrote, but stuff my Dad did when he was a kid would be deemed all kinds of things today.
I didn’t want ‘Homeland Security’ to home-in on this thread… or me… 
LOL…surely people realize things that were done as a youngster are just that…things only a kid would do. i dont plan on sitting a ditch on fire so i can jump it with my bicycle nowadays either, but i sure tried it at age 10:D
Unless ‘said things’ were illegal… then it’s best to not say…