Sight is garbage - BSA Optics Sight System w/ Multi Purpose Reticle

Mounted this on a 7.62 x 39 rifle and was pleased to see my first three shot group was only 4 inches off to the left, turned the adjuster screw and had the same location for the next three shots. Turned it a five more clicks and when I returned to the fire position the dot was up in the top right corner of the viewing area..... At that point it would no longer respond to adjustment of any sort and after I removed the battery to try reseting the unit with no change. Cost me $10 a round for the six rounds i actually got through this thing before it broke. Do not buy one of these.