Doverham,
About 10 years ago I loaded 1 oz 7 1/2 Magnum shot with the BP LB12 wad + overshot wad in AA hulls w/23.5 gr PB as per the BP "High Performance Loads for Clays" manual.
I don't have any specific performance data to give you other than my notes in the manual say "Not Worth The Effort". If I remember correctly I was trying to improve grouse & woodcock range performance in a gun that was choked .010" & .020".
Since RST came out with their spreader loads I've stuck with that for most of my grouse & woodcock hunting. It doesn't open the pattern dramatically but it does give a very even distribution of shot w/o dense centers.
