Good choice. I'll add this, sabots are EXPENSIVE, especially when a kid is learning to use a gun. $50 bucks worth of fosters will teach you a lot about a slug gun $50 worth of sabots will nearly fit in your shirt pocket. It's cheaper to shoot nearly any centerfire rifle made, including premium bullets, than to stoke that rifled barrel.
My daughters 500 Mossy will flat shoot though. Rifled barrel takes those Barnes Expanders out past 125yds. easily. About all the woods are 75 yd shots max though so it rarely matters.