BSA Optics TW4X30 - Manual (Page 5)

USING A BORESIGHTER: Follow the instructions that came with your
boresighter and install the boresighter in the muzzle of your rifle lining it up
with the scope as close as possible. Looking through the scope (as though
you were going to shoot) you should see two sets of cross hairs. One set is
a plain cross hair (this is the one in the scope itself) and another set which
is graduated or on a grid (this is the one in the boresighter). These cross
hairs should line up with each other vertically, horizontally and in complete
alignment. If the vertical and horizontal cross hairs are not parallel with
each other, adjust the boresighter in the direction it needs to turn in order to
achieve this.
CAUTION:
BE SURE THAT THE FIREARM IS NOT LOADED.
PRACTICE SAFE FIREARM HANDLING AT ALL TIMES.
4.) ZEROING
The next step is to test ammunition. NO two ammunitions will behave in
the same manner when fired from the same rifle. This may be one of the
most important steps in sighting in any firearm and is the one that is most
frequently omitted. DO NOT bypass this step.
• Holding the crosshairs steady on the target, squeeze off a round.
• Repeat this two more times to get a 3-shot group.
• Retrieve your target and triangulate the shots to get an average point of
impact. Measure from that POI to the bulls eye where you aimed.
• This measurement can now be adjusted with adjusting screws located on
each turret knob. The Tactical Weapon™ TW4x30 is 1/4 MOA, that means
one click will move the bullet 1/4” at 100 yards.
NOTE: If you zero at a different yardage, say 50 yards,
one click will move the bullet only 1/8” at 50 yards.)
Once you have adjusted the windage and the elevation, you are now ready
for another 3-shot group. Repeat this process until you are satisfied with the
results.
NOTE: It is important to allow the barrel to cool down in between the 3-shot
groups as heating of the barrel can cause bullet flight to vary. It is also
recommended to swab the bore between shots with a dry patch to reduce
buildup. DO NOT use any cleaning fluid or oil on the swab, as this can affect
bullet flight. If you are sighting in the firearm for hunting deer you may want to
adjust the elevation an inch or two above bullseye at 100 yards. This will give
your firearm extended range and still keep you in the kill zone at 100 yards
and less.
After zeroing, use the hex wrench provided to remove the windage and
elevation drums amd re-position them so the that the (“0”) lines up with the
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