I go the other way, but I do a lot of paper punching, I like something with at least 16 power, to see the holes at 100 yds, I even have one with a 24 power, and another with a 32x, but for hunting purposes, you will find it rarely necessary to go over 6x. So a nice old weaver fixed power scope, or even a vintage 3/4 inch tube weaver, or lyman, or burris or redfield, would really fill the bill nicely. I would even say get an air rifle rated scope, they usually have a very short distance rating for being parralax free, and you really want this when hunting squirrels with a 17; because you want to go with headshots.
Otherwise, if you dont do a headshot, you will just blow them up, like a bomb, this applies to any game smaller than fox, if you hit it with a 17 , you simply rip it apart.