james, i'm a bit concerned that you are shooting squirrels at 250yds. how in the heck are you seeing them let alone hitting them?????
I'm an airgunner and whilst i know my gun will shoot 45yds+ i restrict my shooting to 35yds to be sure of a clean kill everytime, the more distance the more chance of wounded game/vermin. Are you going to go looking for a 3 legged squirrel if you misjudge the distance? i dont think so. It's in everyones best interest to give even the vermin a humane death. I'd rethink my max distance if i were you, but thats just my view.