Dude270: You do NOT mention what the uses will be for the sons Rifle in 17 HMR but I assume Squirrel Hunting and plinking with some "range work"?
Anyway my favorite scope for my several heavy barrel 17 HMR Rifles is for used Weaver V-16's (4 to 16 power variables with adjustable objectives)!
These work superbly for all manner of small game and Varmint Hunting - along with doing great duty at the range.
Best of luck to you with what ever you decide on.
Hold into the wind
VarmintGuy