You might want to try an air rifle scope for your rimfire squirrel hunting needs, because most can be parallax adjustable down to 10 yards. I like to zero my Kimber Classic rimfire bolt gun, that is fitted with a 4-12X Simmons air rifle scope at 50 yards. Now...to shoot a squirrel at 5 or 10 yards, you'll have to aim approx. 3/4" above the squirrels head, because the scope is mounted higher above the bore.

I like to squirrel hunt --- when I'm not using a shotgun --- with 22 long rifle, Fiocchi subsonic hollow points, because the muzzle's report spooks the squirrels less.

I like to wear camo clothing with a blaze orange vest, Gore Tex snake boots, eye protection and a set of camo Howard Leight amplified hearing protection muffs; which amplifies sound around 125%. Get a good set of pruning shears or game scissors, so as to make it easier to cut off the head, tails, aitch bone an feet of the squirrel.

Don't forget gallon sized zip-lock freezer plastic freezer bags, so you can stuff the freshly killed, skinned and gutted squirrels in them. Have a cooler back in your vehicle, so you can keep the squirrels on ice.