I emailed RS about this powder as it's marketing blurb could be interpreted wrong or maybe perfectly correct.
They say it's a great powder due to its low pressure and bulky nature to be used in all rifles / revolvers which were designed for black powder only .....
I asked them this could be misleading and folk could interpret this as substitute for bp in cap and ball revolvers .
I have seen on YouTube a distinguished bp user using duplex loads of Bp / smokeless in cap and balls without issues ( not advocating this) but would like folks view on this powder blurb..... not had any response from RS yet