I have shot a similar combination in my 7mm-08 using the 139gr Hornady Spirepoint and the 120gr Reduced recoil. So far I have only shot 1 box of the 120gr and the recoil was less but not by 40% it felt more like 15-20%. Honestly I would stick with the .243 but no harm in having him put a few rounds downrange to see if he likes it.
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