I ended up getting the 8 MOA red dot trijicon and installed it on my S&W model 629 44 mag with the 5 inch barrel. I had to order an extra shim to get it to sight in. I love it, small, lightweight and I can honestly think about taking a whitetail at 50 yards, something I wouldn't have tried with just the iron sights.
It was a great addition to my revolver.

Thanks
Dan