Hi Flintfan,
Thanks. I too use Swiss 3F and have good luck with a 648 ball but I cannot get any accuracy from a beeswax lubed 615. At 50 yards the horizontal deviation is 9-10 inches from a rest. The elevation is always fine but the horizontal spread is terrible. With the 648, they would all be touching in the black. I suspect, as always, barrels vary in their performance and what feeds them best.
dave