I thought the Ferguson shooters might find this a bit interesting. The ball on the left is .648 ball slugged through the bore of my Narragansett Ferguson rifle, while the right one is a .635 ball. I have not tried the .635 ball out for accuracy yet. The .648 ball has a lot more surface contact with the bore. I looked through the Narragansett paperwork that came with the rifle and they recommend a .650 ball.
