I dunno if anybody remembers the Nikon 6x40 (or was it 6x42?) they offered for quite a while. It was fine optically, and the adjustments were good too. But it not only had short eye relief (maybe 3", at most) and a VERY short tube. I had one for several years and kept trying it on different rifles, never really getting it to work right, and finally sold the thing. In comparison, the Weaver K6 is EASY to mount!
