Or you can use Federal Flite Control buckshot and throw all of those numbers off. I think Hornady has something similar.
I've tested both the #1 and 00 buck out of my Mossberg 930 SPX. That's an 18.5" cylinder bore barrel.
Here's how the #1 buck did. Basically a wad-sized hole at 5, 10, & 15 yards and a 9 or 10" spread at 20.
That load looks pretty devastating in gelatin.