Joel, I just peered thru my scope at 500 yards across the vacant field next door. At 10x, a ground squirrel will be MIGHTY small in your scope. The recticle will probably cover a squirrel at 500 yards, depending on how thick the cross hairs are. A less expensive scope with a standard recticle will cover about 1/2" at 100 yards. That's roughly 2.5" at 500 yards, about the thickness of a squirrel, but 500 yards is a long shot and it's going to be difficult to keep the crosshairs where you want them exactly. Also, holdover will be very difficult to judge on small targets. At 20x magnification it's much easier to make a quick adjustment and hold a few inches high to compensate for bullet drop. Example at 300 yards you might want to aim for the head to compensate for 3" of bullet drop. At 10x magnification, it's much harder to make those kinds of judgements and adjustments. How do you know if you're aiming at the head or the shoulders or three inches high if the recticle all but covers the squirrel? I'd say that 10x fixed scope is just fine for larger targets like what the military uses them for. A humanoid target at 500 yards with a 10x target is not that hard to hit. But as you know, MOST squirrels are quite a bit smaller than a humanoid target. If not, then hopefully a 500 yard lead is enough for you to run run away very quickly. :)Grab your 10x scope and a coke can. Set the can 500 yards down the street. Peer thru your scope. Is that acceptable to you? Maybe, maybe not. But then again, 500 yards is not a typical ground squirrel shot, at least not for me. Maybe shooterjohn or bzzrd feedr will tell you different.