ninemm,
I carry a S&W 66 in 2.5 inch and alternately a Taurus 669 in 4 inch - both in a Miami Classic Shoulder System made by Galco. The holster fits both guns very well. And you can choose to customize the opposite side ammo holder by using either a double speed strip holder or double speedloader holder.
Plus, it's easy to adjust the harness to get the fit and angle of each component. It's the most comfortable and concealable rig I've tried, and I'm a 5'10" widebody who regularly wears XXL sized shirts. Hope this helps.