Hmmm...it seems google is my friend.
Looks like these guys:
http://www.go2gbo.com/forums/index.p...#msg1098505653
Switch the barrels out on their own with no safety concerns, although it does seem to have an impact on accuracy.
They mostly are talking about Handi-Rifles instead of the Shotguns, but I don't think there would be a significant difference??