Is the top strap of your 617 drilled and tapped?
You should be able to see 3 holes if you swing out the cylinder and look uner the top strap.
If so I believe the Leupold mount, or a B-Square or Weaver will fit.
My Model 17-3 did not have these drilled and tapped holes so I had a gunsmith do it to fit a Leupold mount. Thing with the Leu is that the scope mounts are fixed in location so you cannot adjust fore and aft.
If you do not have the D and T'd holes, you may want to try an Aimtech type of mount. This is a no-gunsmithing mount that uses an aluminum extrusion that screws onto the right side using the sideplate screws (they come with the mount). IMO, this is the most solild style of scope mount.
The Aimtech on my 686 has never loosened and it also allows you to use the iron sights if necessary.
I don't know if my fears are unfounded but I think that with magnum loads, the screws on a topstrap mounted mount will shear off. But then you only need it for your 617 so that should be strong enough.