Mine had an S200 when he was 8, the weight and his ability to carry it was the deciding factor. The 'full size' rifles were just too heavy. The target stock is better than the standard one, easy to adjust it each time they put on a growth spurt. He's 16 and 6ft tall now and has 'upgraded'.
At 8 years old, the power drop off after 40 odd shots isn't going to be the main score limiting factor.
ISP Airstream MK III No 15 which is a bit poorly at the moment and having a rest
AA Pro Sport + Ginb FT8 stock + Bushnell 4200 6-24x
EV2 MK1 + Leupold Comp 40x
Weihrauch HW100 KT laminate
SBFTC Competition Secretary