Even a primer will be too much charge to be quiet with a handgun.
While a primer is loud in a handgun if fired in an empty case, if you use a wax or rubber bullet, it is really quiet. About all I hear is the "bullet" striking a target. And, that is with small rifle magnum primers in a revolver, using .357 Magnum cases.
Clark, one question: When you use a solid metal "filler" in your cases, as shown in you last post, does that filler piece ever move forward out of the case. I am thinking about whether it could tie-up a revolver cylinder or bang into the rifling in the throat of a long gun.