Yes, it is a black powder gun, but that has nothing to do with the fragility of the action. It is not only subject to breakage but can be very tricky to work on; there are no original parts available and not many repros. The cylinder stop is notorious for breakage as it is a spring, and there are four other flat springs that routinely break (the hand spring, the trigger strut spring, the trigger return spring and the sear and cylinder stop spring). None are available except the latter for which a repro is made.
I strongly suggest you resist the temptation to take the gun apart; it is not easy to reassemble and things don't always work like you think they do. Plus, more of those guns have been broken by folks taking them apart than ever broke when being used.
When correctly assembled, and not broken, worn or messed with, they work OK and in fact have a pretty fair DA pull. They were pretty popular (Billy the Kid supposedly carried one) but in .41 they can be brutal as that spur on the grip really beats up on the web of the thumb. The .38 is not bad.
Jim