I don't use RST's, but handload lots of 7's and am hoarding the last of a flat of Winchester Heavy Dove loads that were offered in 7's. I find them an ideal shot size for both 12 and 20 for everything from quail to grouse (both ruffs and prairie). I consider them a tad light for wild pheasant but good for preserve birds.

"Every one must believe in something, I believe I'll go hunting today."