I think the breech plug has a bigger hole in it for BH209. The way I understand it is its harder to light and thats why you have to use only shotgun 209's and needs the different breech plug. I would not use pyrodex. Not that its a bad powder but its kinda dirty. Pyrodex is the origional BP sub. I use 777, is alot cleaner burning powder. Have not used them but always hear good things about Thor bullets. The nice thing about them is they come in different sizes so you can get the size that fits your barrel best. I use FPB's and they are good as long as your gun likes them.