Yeah, I was more concerned on what number shot and choke to run, but I found some good online stuff explaining it specifically for steel, so I think I’m ready for the rabpocalypse next time I’m up there.
As wombat said cylinder or open choke is the same as no choke at all.
The thing with steel shot is that unlike lead shot it will not compress, trying to force a lump of steel through a hole (the choke) that’s too small for it will turn it into a pipe bomb essentially.