Lots of parts in a 20ga Flues to batter to pieces with heavy loads.
3/4 oz, 1100 fps, and as low a pressure as you can get to burn.

They are struck very thin right by where your hand will rest, to get the low barrel weight. And of course the stocks are very lithe as well.

You are on the right track with your request.

It's hard to find the recipe's they require primarily because most loads listed need to actuate an auto loader.

Out there doing it best I can.