Stan,
I used a few boxes of 9s on scales, in California, I found more shot in the birds taken with nines than 8 or 7.5 shot. I mainly use 8s or 7.5 shot for grouse, woodcock, and registered targets. I used 9s during one of our AF skeet shoots and found a lot of pellet bounce back with nines. Never bounce back with 8s.

I killed a few doves last year with some RST 9s in 3/4oz out of my 28. From the limit of 15 birds I had a few hit the ground and took to cover till I ran them. No nines in any of the birds when I cooked them. Maybe RST 9s could be harder than others on the market or most likely just got lucky

Rich