Already said multiple times but I'll add my +1 to the discussion...
First, speak with each of their parents advising them that you think this a monumentally bad idea, and that you have tried numerous times to convice your friends but that they refused to listen to you.
Let the parents know that unless something is done immediately by them to stop this, as their children are their responsibility not yours or society's at large, you will be forced to notify the local police department accordingly so that when they do respond to the inevitable multiple gun calls by panicked neighbours, nobody will end up eating hot lead. It is the least you could do to save your friends from possible...I dunno...DEATH maybe?? They might hold it against you for now, but years later if or when they finally grow up, they will appreciate your sound judgement in saving their foolish little necks.
Should these parents ignore the issue and do nothing to stop their bone-headed kid, when their son has his toy confiscated by the responding officers, is then taken to the station and questioned harshly by a very much annoyed police detective, and finally released to the parents some time later, those same parents should have Criminal Code and Firearms Act charges laid against them if possible. I say...punish the willfully reckless or negligent so their "epic failures" don't damage those of us trying very hard to prevent shooting sports of any kind from being permanently legislated out of existence.
- Fides et Amicitia
"Can't keep my eyes from the circling skies,
Tongue-tied and twisted Just an earth-bound misfit, I"
Learning To Fly
© 1986 Pink Floyd