They were about one third to one half the size of mature apricots. They started dropping a couple of days after I sprayed, which was three weeks ago, and continued for about two weeks. I also sprayed Captan together with the copper, which the CA label prohibits spraying on cot trees after shuck split, not sure why (could be that apricot fruits are sensitive to it). I was not aware of the CA rule when I sprayed, otherwise I would have followed it.
Also, my tree is a third leaf tree, quite healthy and vigorous. It had north of a couple hundred fruits before the copper spray.