Any cylinder with just oval stops can possibly allow the cylinder to jump past a chamber if it is cocked too briskly, causing scaring to the cylinder and possible damage to the slot.
I learned this on my Rogers & Spencer too well- since there is no lead in's cut into the notches, it skipped every time I tried to cock it briskly in the first match I tried to use it in. I slowed down and didn't have any more problems.
Barney Fife: "Nip it, nip it, nip it!"
Andy Griffith:"Oh now Barn'...."