Bob makes good suggestions here.
Especially with the advice to seek all possible load configurations.

On wad and card detail, see here

Felt wads are important.
I use saddle felt, or wool felt sheet sourced from McMaster Carr or similar industrial supplier.
I make the powder cards from milk carton, and form them into the cup/bottle cap shape myself.

Cup over powder, lubed felt disc, then lubed ring-shaped donut wad under the ball.
Nice little stack with self-centering and self-sealing design properties.
Easy to produce, and consistent performance. Lots of lube for nearly unlimited follow up shots.

Cheers
Tinker