great white101 welcome to the forums, my grandson is 11 about 100lbs. and here is what he likes to shoot

10/22 ruger
nef single 410
and my wifes model seven in 260 rem

i had to shame him into shooting the 260, the way i did this was the neighbors grandkids were over and they wanted to shoot some guns they range in age 8-14 so those are the guns i brought out, they all shot the 410 and the 22 then they wanted to shoot the 260, well my grandson wasn't about to be shown up and he also shot the 260, now he likes to shoot it all the time, well along with the 22's, best of luck i think the h&r in 223,243,30-30,260 if available would be fine, i know it will be in a year or so anyway....

oh yea your 30-30 ought to be decent to 150 ish dependin on the shooter