First, you'll have to determine if your 617 and 629 are drilled and tapped for a mounting rail. Prior to 1993 the S&W revolvers were not drilled ant tapped. Easy what to do that is open the cylinder and look for 3 holes in the top strap.
If they have been drilled and tapped you can find some pretty cheap weaver rails. I've seen some that are basically stamped aluminum for about 10 bucks at a local dealer in a wall hanger package. However, while it should work find on your 617 I doubt it will prove rigid enough to withstand the recoil of a 44 Magnum. To put it simply, you get what you pay for and IMO you are better off getting a top tier mounting rail from the get go. As for mounting rings, it's another case where you get what you pay for.
BTW, I would be hesitant about using Burris mounting rings. I paid close to 40 bucks for a set of Burris rings that looked like they were for a Weaver mount but were just a tiny bit too narrow. When I tried to force one on my Weaver rail it snapped like a dry twig.
I'd suggest that you look for a set of Leupold mounting rings, while they won't be cheap they will be very well made. I picked up a cheaper set of mounting rings and while they work alright I have had issues with them shooting loose. Since you are planning on using this scope on a 44 Magnum I suspect going cheap will just mean buying a second set when you find that cheap rings won't stay tight with the recoil of your 44 Magnum.
Bottomline, paying more for premium gear will likely save you the money you waste by trying to go cheap.
