I use 7/8's oz #7.5, just because I use that load all the time. Safe to use in every 12 I own.
This year's prospect. My Shadow Oak Bo grandson.

I need to have a certain confidence in the loads I shoot, and, they have to be safe for all my damascus shotguns.
But not 20 different flavors.

When I test patterns and observe my breaks, and then shoot some libbies, I get a pretty good feeling on what works for me. Some of the vintage loads are pretty anemic, even with 7.5's.

Everyone else's mileage may vary of course.

Out there doing it best I can.