GGaskill, The barrel is steel, made by Dom, don't know the specs. These 2" case hardened balls I'm using are 1/4" undersize so there's lots of room to bounce.
As to what damage they would cause, I don't know for sure and sure don't want to find out the hard way.
DD, that sabot sure looks to have taken a beating, what size is it and how much powder to fuzz the butt like that?