"Mechanical offset", "height-over-bore", whatever you want to call it, is a thing I'm more used to dealing with when using AR-pattern carbines at close ranges than when shooting pistols and revolvers.
Getting this T.O.R.O. dialed-in reminded me that the center of the optical sight is most of an inch above the axis of the bore, and given the wide range of velocities in .38 Special ammunition, it opened a whole 'nother can of worms.
The other sighting system on handguns that has this amount of offset from the bore is lasers...well, most of them, that is. They're usually slung below a flashlight on an accessory rail or perched out on a CTC Lasergrip, like the ones on the old Painted Ordnance "Gun Blog 9" here.
With Lasergrips I've come around to the solution of adjusting them so that the beam is parallel to the bore axis, such that the bullet's point of impact will be about a half inch left and an inch above the dot (on my J-frame) at anything out to something over 25 yards.
There's no real equivalent of that for a MRDS, though, as far as I know.
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