Bios are definitely tougher to break than their predecessors. I use 7 1/2s, 8s and 8 1/2s 100% of the time for sporting clays, doves, quail and woodcock. I like 4s and 6s for crows.

The only thing I use 9s for is ballast in my Allison speedboat. It has right side steering and in order to make it sit level on the pad, which is only critical in excess
of about 75 mph, I put a 25# bag of 9s on the left side which, along with batteries and cooler being on the left side, balances it nicely. 😉

May God bless America and those who defend her.