Glad to help out ...
Try and remember ... for steel, LESS choke than for lead
and shot 2 - sizes BIGGER for steel than than you would
normally use for lead.
Pattern some of the steel loads you intend to shoot at Geese
with I/Cyl & Mod ( I like BB or BBB ) at 40 yards. I'd be surprised
if the I/Cyl patterns weren't the most even & well distributed.
Use at least a 4 foot square of cardboard or Kraft paper, and measure
the 40 yards (120 ft.) just don't "pace it off ". Count each pellet hole
inside a 30" diameter ( 15" radius) circle drawn to enclose the greatest amount of pellet holes centering the total shot charge. Your looking for a pattern that you can't throw a goose through ... and most of your shooting
will probably be less than 40 yards !