The sparks occur whether or not I'm using (A-Zoom) snap caps.

As a sometime flintlock shooter I know that, at least in that technology, sparks are the result of tiny pieces of metal being shaved off the frizzen in a process that makes them hot enough to glow. I can't help thinking that the 442 sparks are likewise tiny pieces of metal being scraped off of either the firing pin or recoil shield. Maybe those parts are hard enough and/or the "missing" pieces are so small that even over a lifetime of shooting the dimensions won't be adversely affected.

If they say it's normal then there's nothing I can do about it. But still . . .