This is my Recipe for 480 Ruger Shot Shells.
Prime the case.
Add approximately 6.0 grains of American Select, Unique, 20/28, etc.
1 each 50 Cal Muzzle Loader Over Powder Felt Wad. Seat with 3/8 Dowel Rod (Felt Wad is app .0130 thick)
Add approximately 150 grains of shot (7.5, 8, or 9) Fill till you only have enough room to seat the Gas Check.
Install Gas Check Cup Down
Add Roll Crimp.

Out of my Alaskan this is a Super Snake Load. At 5 feet it will put down a uniform pattern in about a 6" Circle. The Gas Check and Wadd will blow a hole in the center of the pattern.
I worked with several different combinations of wads, and this worked the best. It will kill a snake out to approximately 10 feet.

Bob R