when my 13 year old daughter was 8 she was shooting this same rossi single shot 223 with 55 grain rem...(now we use the 64 gr cause they group better)...my 8 year old now shoots it.
my oldest shot it out to 282(she remembers lol) yards no problem...i use it out a lil past 450 myself, and know guys who shoot over 600 yards with it.
223 is gonna kick less than a 243. a 243 doesnt kick that hard, but more than a 223. the 44 mag i dunno..
it takes time and dedication to shoot good, so because RR can go and shoot 1000 yards, dont mean you will tomorrow, but could someday.
for my daughters, I find it that if you would just go shoot a box of yer dads 30-06, it will make the 243 and especially the 223 seem to kick alot less....
maybe just hamburger yer arm 1 day, and i think you will find the 223 to kick like a 22lr.