The last time I had some was last year... and they were terrible.
They came packaged with a Walther PPK BB pistol kit I got on sale from Cabelas. Most were unevenly covered, say 1%-4% un-coated surface area. I tried "using them up" in a Marksman 1010 (since it isn't all that great itself), but the difference between the Copperheads and Avanti steel shot was very obvious even in that.