The indoor range by me only lets 2 in a stall at a time? might have to have one kid sit out while you have the other one shoot? My 9 year old is ok with shooting my 22, his 22/20 ga, and my .223. I let him shoot my 22 handgun a few times with me standing behind him helping. He liked my .223, is a good round to start on center fire rifle with, not much kick.