Don't use plastic wads witk BP , they'll melt - Pyrodex and plastic is ok . From test I've done in my guns [ that may not apply to other guns ] - I was useing brass shells and hand tools to reload and found blown patterns when wad column height was increased more than a 1/2" . Also, anything thicker than the thin , .030, overshot wad was used caused blown patterns . BP volume is the same weight , but Pyrodex weight is much less , I think 70gr is equal to 50 , so you'll get more loads per pound because you load by volume but buy in weight . There's some savings there .
http://WWW.circlefly.com sells paper wads and has loading advice on his web site . I don't agree with useing 11ga nito cards in the brass shells - from MLing I like a tigher fit so I use 10ga nitro cards . Also use the thin OS cards and glue.
