I have two recipes that I use for a couple of old Parkers:

12g. Federal paper 2 3/4, 17g Red Dot, CB 1100 wad, 1oz lead. ~5000 psi

16g Cheddite 2 3/4 plastic, 19g Solo 1250, SG16 wad, 1 oz lead. ~7100 psi

Could bismuth be substituted (volume due to weighing a little less than lead) directly?