The wedge can shake loose whether the arbor length is correct or not, hence the reccommendation to tap the wedge in until it is tight, which makes it harder to shake loose. On a gun with too short of an arbor, tapping the wedge in until it's tight can bind the cylinder. Not tapping it in all the way(using the wedge to set the cylinder gap) can make the wedge easier to shake loose, which in turn has all sorts of negative effects, like battering the wedge, battering the recoil shield and changing the cylinder gap. On a gun with an arbor of correct length the cylinder will not bind when you tap in the wedge all the way and the wedge will be less likely to shake loose because it is in tight, which helps protect the gun from the aforementioned negative effects. Is that a fair summation Mike?
