I had one like jismail had on my 183-series Mini and it was worthless. I never could get it to zero because it moved around so much. I took it off and went back to irons.
The scope mount that takes the place of the rear sights works pretty well I've heard, but you loose the ability to use your iron sights.
As far as the B-Square mount for the Mini, some people have reported good results with it because it has a couple of set screws to help eliminate movement common in the other brands. I think you have to be very careful not to try and overtighten these set screws as I think it's fairly easy to strip them out.
Short of having your non-ranch Mini drilled & tapped for a scope mount, I dont think there's any real good solution available installing a scope. The guy who does come up with one though will get very rich.
Fear is a Reaction..............Courage is a Decision