I can't comment on effectiveness of .357 for deer, and don't have any kids so take this for what it's worth. I love my Marlin .357. All the talk of the lack of quality in the newer models had me worried, but I must have got lucky as I have zero issues with the one I bought a couple years ago. My nieces and nephews have shot it without trouble (age range 7-14) at a range of around 60 yards. No, the younger ones can't load it. Yes, they need to be supervised to learn to use it safely. I bought the XS sight systems peeps and rail, and mounted a Leupold ultralight fixed power (2.5x) in QR rings for the best of both worlds. It's one my most fired rifles, enjoyed by everyone who shoots it.