As long as it is accurate in your gun, I would just use the 90 gr Fusion load. Especially at the ranges your son is likely to use it at over the next few years.
It’s odd my savage msr 15 224 Valkyrie will not shoot the federal fusion for some reason. 6 inch groups at 100. It will shoot the 75 grain Hornady Black 5 shots into a nickel at 100
