If you want a scope set-up that works right you really need to drill and tap the top strap and install a good quality base. Wiegand makes a good base (weaver style). I have one on a Blackhawk 41Mag and it stays put, unlike the Square B clamp on base that I tried first. That clamp-on setup wouldn't stay put, as in every time I shot it I would have to rezero because it would shoot 4" to the right. I tried to tighten that thing down till I was afraid of stripping screws or breaking something but to no avail. If you are interested in the Wiegand they have a website and shipping is prompt. I would advise to have a smith install the mount though, I drilled and tapped mine myself and would not do it myself if I had it to do again FWIW.
