All I've used is 20N29. It's so slow that there might not be a cartridge smaller than the 50BMG that can't take a full case and still be under max pressure.
I have never used it for anything other than 50BMG. Are you suggesting you have found it useful in any other caliber?
I guess if I had a 25 Weatherby, or something like that, I might try it just for giggles.