Also I have noticed that if I sight in a gun during the summer I have do a final tweeking to it during Sept when it starts to cool down. Just try to shoot in the morning. Your range doesn't open till noon which could be a probably. Maybe look for a different range or if you have State or BLM land. I know in MT you can shoot on State or BLM. Get a range finder and set up a range that you can set up.