A lot of people use a side mount for standard scopes on the nagant, which requires the bolt handle be turned down in order to clear the scope. I have seen people use a forward mount which mounts on the rear sight (sight parts removed), and works well with scout and reflex optics. There are rail versions as well as the one pictured. There is also a mount which requires the front ring be drilled and tapped as well as the bolt handle modification. Cost of parts for these things is usually pretty low, I suggest getting a good gun smith to drill and tap and do the bolt modifications. Not getting the holes lined up and straight will make your scope crooked, and a poorly done bolt handle can break off.
Scheme well, scheme often.
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