Whoops, I misread your comment. Er, no, Smith & Wesson never made any
cap & ball revolvers. They used black powder in their early cartridge guns, though. The .38 Special was introduced as a black powder round.
Just for fun sometime, load up some .38 brass with black powder, then go to the range and shoot it up. See how long you can go before the cylinder binds. Then schedule about an hour afterwards to clean the thing.
Thanks for the clarifications regarding antique firearms. I'm not familiar with them at all as my post clearly indicated. Sorry for passing on misinformation.