I bought my son a Mossberg super bantam 500 in 20 gauge because of ammo and stock extensions. I bought it when he was 8 and he out grew it very fast. We also bought a Lee Load All reloader (about $60.00) and made some real light target loads these got him over the "kick" fear of shotguns and now he makes and shots some really hot 20 gauge steel loads out of the "Status of Steel" manual from ballistic products - with #1 shot in 3" shells he is folding up large geese up here.
If you get a reloader be sure to get their digital scale – especially for hunting loads.
I never seen any real good 410 in steel/non-toxic shot.
https://www.mossberg.com/products/shotg ... per-bantamhttp://www.ballisticproducts.com/Status ... /00MSTEEL/