I have had a history with slingshots going back to my kid days. I remember coming back from the fields with my handmade wooden slingshot in my back pocket, there was a male robin standing on a fence post. I pulled the slingshot out, always had a nice round stone in my pocket, loaded the slingshot, went to full draw, aimed right at the breast of the robin and let fly. The robin was knocked clean of the fence post and lay as if dead. I walked up, kneeled down and can remember to this day the sorrow I felt for the innocent bird and why did I have to do this awful thing to such a pretty bird. To my utter amazement he blinked his eyes, looked around very startled and quickly hopped away, later to fly off into the trees. I learned a valuable lesson that day that stuck to me through my life, never shoot at anything that doesn't present a clear and present danger or isn't intended to be eaten.
I've changed my tune a little and have used a more modern and highly accurate aluminum framed "flipper crutch" to motivate stray animals off my property.