I just pulled my 686 12 gauge out of the safe. First, there is no rattle. Second, it fired on snap caps while upside down.
The 686 has inertia triggers. As a rule they shouldn't fire the second barrel on a snap cap unless struck on the butt pad with the palm of your hand to reset the inertia block. By the way, you can take the forearm off and open and remove the snap caps and the shotgun won't cock with the forearm off. I don't notice any noise with my 686 also, but to qualify that statement, I've been told my hearing is atrocious. Not sure what my wife means by that, I rarely hear what she says.
