It's been 10 or 12 years since I loaded round balls in the 12 ga. My load also comes out of Lyman's Third Shotshell Handbook. I never hunted with the load; we just shot it for fun. I don't remember doing any kind of accuracy testing on targets, but I do remember consistent hits on a pumpkin at about 35 – 40 yards. I was hoping for a dramatic effect, but it just punched clean holes through and through. The firearm was a Mossberg 500 with a rifled bore and iron sights.
.690 Pure Lead Round Ball
Case: Winchester AA
Primer: Winchester 209
Powder: 37.0 gr SR 4756
Wad:
Winchester WAA12 w/ petals removed
Two .125” cards (I think I used Butler Products Brand)
Roll crimped
I also have the note “Accurate Load” hand written and highlighted next to the load, so I must have liked it. As I recall, I used one of those Butler Products roll crimpers that are used in a drill press, and I had to trim a little bit off of the case to get the crimp the way I liked it.
Jeff