Last weekend I loaded an ounce of steel BBB in ancient (blue) one ounce wads over 29 grains of Herco and tested them in my coach gun.
The good news:
My short coach gun barrels show no marks from steel at all
and at 12 yards my loads absolutely destroyed a paper target. All 33 pellets were on paper in about an 18 inch group. That looks like a GREAT bedside home defense load.
BUT - the bad news is that at 25 yards not one pellet from both barrels touched a milk jug. NOT ONE PELLET!
I have no idea where they went! I suspect that I will need a BIG piece of cardboard to find out the 25 yard pattern.