FOC is important, but if he plans to hunt deer with these arrows, overall weight is more important. Just saying not to sacrifice overall weight in a quest for FOC. Of course, if you can get good overall weight and most of it’s up front, even better. I killed my first whitetail as a teen with a 42# recurve, cedar shafts and 130-grain two-blade (Bears with bleeder blades removed) and got good penetration. I have no idea what arrow weight or FOC were. 😆