re: 6.5 year old first rifle

They are both off of the .308 case one shoots 6mm bullets the other 7mm. 7mm-08 give the option of heavier bullets but will have a bit more recoil and less velocity so it won't be as flat shooting but is arguably the more versatile gun. Never had much to complain about with my .243 and it was my first deer rifle given to me for my 11th birthday. Killed probably 7 or 8 deer with it. The muzzle blast bothers most kids more that the actual recoil.