I like the various fiber optic sights. Check before you order for the 617, most are to tall. The 4566 should be fine with plain fiber optic or TFO's (tritium/fiber optic) if they make them for that gun.
I can't remember seeing any of these sights before, who makes them? I have a set for my Redhawk but, none for my S&Ws. Front sight in top picture looks quite a bit thinner than your second picture?Old said:Older post, but here's what I added to my Model 617.
First pix is the sight picture for the Bowen Classic Arms "Shallow Vee" rear sight that I added. I really like this sight setup for plinking and hunting and it works pretty well on targets too. For my eyes, it works almost like a peep sight, with the front gold bead lining itself up easily/quickly in the shallow vee. My Rugers were done this way, and all my S&W revolvers will soon be setup this way too...
Here's a close-up of the gold (polished brass) bead that I added to the stock 617 partridge sight.