A revolver. Cmon don't tell me you think it lands on bullets perfect? Ignorance is bliss.
Doesn't the cylinder have notchs that lock into teeth so the bore lines with the barrel, those teeth are also engaged when the hammer is pulled rotating the cylinder for the next round? if your cylinder is rolling freely in a way that you can't even hit the primer you should probably take it in to be fixed.
If thats what you were talking about anyway, but I dunno. Ignorance is bliss after all.
Why the forget would you shoot yourself with it?, you should only aim that toy at things you intend to destroy,
like your friends.