Equatorial mount counter weights?
Too much trouble.Just fill the box with rubber mulch.Duct tape it all the way around, all over.Duct tape is cheap at Harbor Freight.Staple target to cardboard and use a nail to hold it on the box.When the front of the box gets shot up....tape it again and use the other side (s).If you have a box with large sides/bottoms, you have six aiming areas.(Note:Boxes are free at the Post Office.)Again as the box gets shot up, tape it again.It will last forever..