Archer airguns - http://www.youtube.com/watch?v=lLirsAFpsfE
Is it possible that one or both turrets are at the extreme end of their range?
When the elevation/windage adjustment knob is far from its center position and reaches its
extremely end (most up or down for elevation, or most left or right for windage), sometimes you still can
turn the adjustment knob, but the reticle will not move.
There is a free spin zone in the scope sometimes. Meantime, in this situation, the
crosshair is far away from its optical center which may cause many problems that is difficult to identify
the causes, such as not holding zero (Point of Impact scatter around without
It is recommended to keep the scope on its optical center for the best
When you have set the zero have you been sure to lock the knobs down - When the center hex
screw is fully tightened, the knob is locked and is not rotatable. This is so-called Locking
position. When locked zero position should not move if it has been set correctly.
To reset it if it is locked loosen the screw a little bit and the knob pops up slightly
(sometimes you may need to pull to disengage the locking), you will be able to turn the knob and
If you further loosen the screw and let the knob pop up (or pull) to the outmost position,
the knob is in the re-setting mode and it can freely spin to align the marking of your turret to the
starting point without affecting real zero point.
Another possibility - I had a similar problem in September, the issue in the end turned out
not to be the scope but the rifle as customer went on to test with another new scope and had the same
With the above analysis, try the following sighting in procedures:
1. Try to bore sight it with a laser or optical boresighter.
2. Make sure the distance between the target and the scope is appropriate. Over 30
yards (90 feet) is better.
3. Make sure the boresighter is perfectly parallel to the barrel, assuming that your barrel
is parallel. Rotate the boresighter to properly fit it into the barrel, making sure that the laser dot is
stable and consistent.
4. Check the mounting system to make sure that the front ring is not higher/lower than the
rear ring and the mounting system is straight in installation.
5. To find the middle position in the windage adjustment range, rotate the knob to one
extreme end, and then rotate the knob to the other extreme end. During this process, remember
how many rotations you made. Then, start from one end to adjust the knob to one half of the total
number of rotations. This is very important - because when the windage adjustment knob is far from
its center position and reaches its extremely end, there is no space for crosshair to move
6. Adjust the elevation of scope, making sure that it is well centered in the up-down
direction. Do it as step 5.
7. From this “centered” position, if you can turn the adjustment knobs without difficulty,
but the Point of impact (POI) is far away from crosshair, adjust the mount or rings first to get the POI
closer to the crosshair before adjusting the windage/elevation of the scope.