Back when Tasco was made in Japan they were the top dog in the optics world in their day winning optics of the year for their World Class line of scopes. I forgot in an earlier post I have two of them. Back in the early 90's they introduced the bullet drop technology by offering rings for the elevation that were designed for specific loads. Won optics of the year at one time.People buy old Tasco Japan scopes..No warranty on them but they feel it is a good scope that should not give them any trouble.
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.55 grain at 2900 fps used one ring, .30 cal running 2700 fps used another. You had to shoot the caliber/fps for them to be accurate at the long range drop.
Why Tasco decided to go walmart cheepo is beyond me, but they are still around and Nikon is gone.
Personally I think Nikon got tired of producing a quality optic that was trying to compete with budget models for market share. So goes economics.