a 12 gauge ball weighs a ton. there is a reason the slugs are hollow. that powder goes off, and the gases and such hit the ball and it takes maybe 2 times as long to get moving as a slug.
keeping in mind you face, eyes, and hands are right near there...where do you suppose the gases and explosion are going to go, in your relatively weak break action, thin walled barreled shotgun?
don't call me for a ride to the emergency room, i don't want blood on my seats.