Originally Posted by Yorkshiretea
I'll save you some money
Notice on this example of what looks like a knock off Mk.4 is that the 'pusher' from the turret is not attached to the erector tube. On the opposite side is a leaf spring which provides the return push when you dial the turret the other way, this can get lazy especially if the turret has been screwed down tight against the spring.
On thing I like about the SIII Sightrons is that the end of the pusher is physically attached to the the erector tube, so that when winding back, the tube is pulled which assists the return spring.