Got a question on the old buckhorn sights.............the type you see mostly on winchester rifles...............are the sight elevators you see in the middle of these sights graduated for yardage..........each time you move the elevator up one notch does this correspond to say a 50 yard increase...........or these just intended to set to a specific yardage and left alone????????

I'm sure the one on my Marlin is intended to be left alone after it is set. The spring that holds it all together is quite stiff (I know, because I broke one and had to replace it), and there are no markings that suggest different ranges.

They're pretty much intended to be left alone, but you can certainly use them to adjust for range. You'll have to experiment with the load you're using to see how much each notch will change point of impact, then go from there.