No it was not a serious question, just a rhetorical one for the guy said if you don't use BP why use a sub, why not just use smokeless. It was to point out that some times smokeless is not an option. Handy hints (not you I know) like getting together with some friends and order a larger quantity of BP to spread the cost of Haz Mat fee. Like I could not have figured that out myself either. I know one other guy who sometimes shoots a Ruger Old Army, he might be interest in a pound of FFF more likely he would sell me a pound he has stashed that he will probably never use, if I tell him I really need it. I have been using Trail Boss in my more than 100 year old Smith and Wesson New Frontier in 44-40 but think Black or Pyrodex would be a better choice. Mostly I just don't shoot it. I am not comfortable with smokeless loads for the Double Rifle. I know others have done it safely but I paid $2500 for it and it is worth double that. I can't see risking it with smokeless so my stash of Black goes to it and my other guns get Pyrodex. I can afford a $50 pound of BP but when I can buy a pound of Pyrodex locally for less than $20 I don't see the point of springing for the Black. Actually, I have not shot either of my cap and ball pistols in a couple years or my two percussion rifles. I did shoot my Swedish Roller with Pyrodex recently and the double rifle with black. I have some 777 I got locally that I have not tried. Like I said, I can get Pyrodex or 777 at the store sometimes but no Black or smokeless. I can get smokeless at the a local gun show but no Black. The OP asked about Pyrodex and he got some good responses and some that I thought were not so good.
Tim