I reload quite a bit of buck for fun loads. 12 gauge with 00 in plastic hulls and 00 & 000 in brass hulls.
Use 12 gauge card and fiber wads for loading plastic hulls.
I also cut and place a few wraps from a paper grocery sack inside the hull before placing the 00 buck to act a a poor man's mylar sleeve.
Tried cutting petals from AA type wads, but got inconsistent results ( POI).
You can pick up the reasonably priced wads at your black powder shop.
I do all my wad seating using hand punches and rods to seat the wads.
A MEC wad guide does help seat the fiber wads into the plastic hulls.
9 - 00 pellets are 1 1/8 oz.
My main load is a full charge of Herco. Alliant older guides showed the loadings for Herco.
I do load some with Promo at light - 1150 - trap levels for smaller stature shooters.
Brass hulls (that I add a slight mouth crimp to for cycling through a pump) take LP primers with Herco,
11 gauge card and fiber wads, and a 10 gauge over shot wad.
Over shot wads are glued in with waterglass, Duco cement, or (in my case) Elmer's glue.
I also use the paper sack strips as a wrapping around the payload in the brass hulls as well.
If you have ever heard the 'ching' that a brass hull makes when cycled out of a pump, you would know why a person takes the
extra effort to load them.
JT