Mike , I fixed S/Ws for 20 years and changed a lot of rear sight blades/slides whatever you want to call them to accommodate for taller front sights and changes in sights on target revolvers. The rear sight assembly is pretty tricky, depending on the model, when they were made , if they are bent, the sight body, not the blade you have to straighten that out. Then it has to be staked properly with the right tools. Generally you are taught to always start with a new adjustment screw etc. Anyway trying to talk someone through it on the computer is just not going to work. Believe me it can be frustrating to someone that has been trained and does it regularly. If you want to study how SW revolvers work buy the Kuhnhausen Revolver manual from Brownells. I can understand wanting to fix it yourself, But you are starting on a hard project to begin. The 17-5 is a nice gun if you are still having problems with the rear sight on your gun PM me your address and I will be glad to send you a rear sight assembly for your gun. You will need a set of mini-screwdrivers, I like the Husky brand you can get at Loews or any other that has the blades in the handle and spins. Will send new mounting screw for the sight tang also.
Put the frame or your revolver in a vise, so its setting level and wont move,padded jaws best. Slide the elevation stud into the slot/keyway until its all the way forward , and the hole in the tang lines up with the hole in the frame. The tang will be curved up from the frame( thats normal) push it down with your thumb or finger, and start the screw into the tang with your fingers , once its secured by several threads you can let the tang up and finish with the screwdriver. I try to get the screw down as far as I can before I let the tang up. Then just adjust the sight as you need to. Let me know, Glad to help..
Thank you once again for all the information. I replaced the too-low rear sight blade with what I think is the correct part, test it to see if it was close, then struggled (STRUGGLED) to get the microscopic screw and plunger in, so the click-stops work. After an hour, all was fine. I took it to the range and sighted it in, and now the gun works nicely with a sub-6-o'clock hold. Using a rest, I get roughly a one inch group, and I can get a decent group shooting normally.
I plan to take the gun to the range again, and try it at 50 yards. Hopefully my sub-6-o'clock sight picture will work the same, or do I need to adjust the sight every time I go back and forth between 25 and 15.
I now feel very comfortable with this gun, as if it fits me as well as I fit it. I'm much more confident shooting it. Thank you for all the advice, and everyone else too!!!!!