A few thoughts, which might or might not be of help:
Are you using the Federal case that is specified in the load data? At least, I think it's specified - I don't have my IMR book here right now. I know of at least 4 Federal cases currently being loaded by the factory, 3 if you disregard the paper shells.
Is the Load-All actually dropping 22.5 grains of powder, or are you relying on the powder bushing to be right? If it's dropping light, might cause a dished crimp.
A 20 gauge card wad inside the shotcup will raise the shot column.
As George said, maybe a Federal 12S3 wad in a Federal shell will work better for your application.
DC