I would love if one of my girls would be broody, but they are still young so, maybe next year. I don't remember coming accross any information about Magpies being broody. I'm sure that some must, but I don't know if they would be as good as muscovys are.
 
I just put the eggs that I want to  hatch under a broody chicken...I have 3 magpie eggs under a silkie right now!!! They are due to hatch any day now I can't wait. I had a few under a first time broody a few months ago and she killed one when it hatched, and the others didn't hatch. These eggs I have under my silkie who has hatched lots of chicks in the past so I'm sure that she'll do good... I'm on the edge of my seat waiting for the eggs to hatch!