Checks, wads and fillers.
You guys got my brain in low gear.
Now, why not use the pithy paper egg cartons to punch out discs of groove diameter?
Could soak the carton in Bear grease or any lube, grease , wax, before or after punching. Wax of some kind might be best, to not contaminate powder. Redbear's wad of bunched up wax paper sounds like it may work also if you could use filler.
Think I may try some in the .357 or 40 65.
Will try in straight cases first and not worry about sticking them to the boolit.
Life is good