First off hello to the group.
I had a similar problem with a 24S-E, almost. Let my son shoot a hand full of 22’s at a 55 gal burn barrel. Put the shells on the ground and while picking up one it must of had a pebble on the rim. When he slammed it shut the round went off. I ran over to look at it and it looked like the barrel had I crack in it. Put it in a case and was in storage for about 10 years. Brought it out one day and took a good look at it and what I saw as a crack in the barrel was actually the rim of the 22 shell peeled back. Great little combo gun in 22-20 ga.
