What a waste,... Zeroed it at 15m, then 25, then for some reason my shots were off, so back to 15, 25, 50, groups all over, WTF. Spent 4.5 hours then I notice the cross hairs flopped to the left when the rifle was tipped left and they flop right when the rifle is tipped to the right....The whole frigging crosshair holder is loose in there. Not sure if I should crack it open and try to fix. circa '30s mossberg long tube scope. fug.