Update. Ordered a Skinner aperture soght with the 0.600 post. Local gunsmith installed the post today and to the range I went. No filing was needed and only a little windage. 1.5 inch 5 shot groups at 25 yds, probably as good as I can do with trifocal vision. Think I've got my farm gun. For precision work I'll grab my bolt action with a scope.
