I use 5/8oz and have for a few yrs. Before that 3/4oz was my favorite.
Most all my guns are Full choke so range is not an issue. Either will reach easily to 40yds and a bit beyond and break birds.
I started loading yrs back with a low pressure recipe right out of the Lyman manual. It was for a 1oz (7/8oz?) load. Then I just kept reducing the shot load a little bit at a time. Still using the same wad. I just fill the extra space over the small shot load with a couple Cheerios and they crimp perfectly. I'm not choosey about hulls either but I know that'll make many worry.
No problems, everythings still in one piece incl me. All pre WW2 guns and many pre WW1. Some Damascus too.
The orig recipe was using Clays. When that got hard to find a few yrs back, I switched to ClayDot. Use the same 'bushing' in the MEC9000. I think it drops 14.4gr. A little bit heavier than what it did with Clays. But that's what it said it would do.
Skeet & SC w/a Trap gun,,,long range fun.
