Mike,

I have never used a round ball in a shotgun. I used to shoot a .50 cal hawkins using a patched ball. I would hazard a guess that with out rifling, you will loose accuracy rather quickly, but I could be wrong. Wasn't that known as a smooth bore musket?

BP has these:
.715 ball
http://shop2.mailordercentral.com/bpicart/prodinfo.asp?
number=0377150
.690 ball
http://shop2.mailordercentral.com/bpicart/prodinfo.asp?number=0376900
.690 mold
http://shop2.mailordercentral.com/bpicart/prodinfo.asp?number=1245690
AQ round ball
http://shop2.mailordercentral.com/bpicart/prodinfo.asp?number=0151000
Round ball slug brochure
http://shop2.mailordercentral.com/bpicart/prodinfo.asp?number=00BROUND


Pete