One of the things that Long Range BPCR shooters have to contend with that
Silhouette and Short Range shooters do not, has to do with the height of the
rear sight eye cup. For example, when I shoot in a Silhouette match, my rear
sight elevation settings are as follows:
|Rear Sight Elevation
In contrast, when I shoot at a Long Range BPCR match, my sight settings are as
||Rear Sight Elevation
|� 800 yards
|� 900 yards
|� 1,000 Yards
The need to use dramatically higher rear sight elevation settings brings with it
two (2) specific problems:
1) The need to use some type of raised cheekpiece to bring the shooter�s eye
into alignment with the rear sight eye cup (for more information about this
point go to �Cheekpiece� under the �Equipment� heading on this web site), and
2) The need to alter the position of the rear sight staff in order to provide a
clearer sight picture.
Try This Experiment
Take your rifle to a safe place (without any ammunition) and set it up just as
you would for a match. Use a gun cleaning cradle, shooting bags, or your
cross-sticks. Run the rear sight up to a setting of 175-180. Now look through
the rear sight eye cup at a target located 700, 800, or more yards away. Pick
out a house, a large tree, or some other object that you can see through your
Now look through both the rear sight and your front sight, just as you would if
you were aiming at a target in competition. If your rear sight staff is in its
standard position it should be perpendicular to the bore line of the barrel. If
it is, you�ll have a distorted view of the target with the rear sight eye cup
run up to this position. Why?
Because the eye cup on your rear sight is up so high that you�re having to look
down at the front sight, rather than through the front sight as you would if it
were down lower. The bottom portion of the threaded shaft of the eye cup is
actually partially blocking your view of the front sight.
Now, while still looking through the rear sight, gradually lean the top of the
staff of the rear sight forward toward the end of the barrel. As the rear sight
staff is leaned forward, you should begin to see a clearer picture of the
target, with any glare or distortion greatly diminished or eliminated entirely.
This is because the threaded shaft of the rear sight eye cup is now pointed
directly at the front sight, not several inches above the front sight as it
would be if the staff were in its normal vertical orientation.
Look at the pictures below to see the difference.
It�s All In The Angle
Notice in illustration �A� that the difference in angle between the red and blue
lines is very small. That means that the shooter�s perfect line of sight
directly through the threaded shaft of the rear sight eye cup represented by the
blue line (i.e. horizontal to the bore line of the barrel) is very close to the
actual line of sight through the front sight (i.e. what your eye is seeing)
represented by the red line.
Notice in illustration �B� that the difference in angle is much greater. Also
notice in this illustration that the rear sight staff has already been leaned
forward several degrees to compensate for this factor. Now the threaded shaft on
the rear sight eye cup is pointed directly at the front sight and the shooter�s
sight picture has been greater enhanced.
The problem is worse for those of you who have a shorter barrel (30�) than it is
for those shooter�s who are shooting a longer (34�) barrel. The angle with the
rear sight elevated is even more pronounced with a shorter barrel than it is with a
longer barrel because the sight radius is shorter (i.e the distance from the rear
sight to the front sight).
How To Correct The Problem
The cure for this problem is to loosen the screw holding the rear sight staff in
position and tilting the staff forward until a clear sight picture is obtained �
then tightening the screw to hold it in place.
After you have completed your Long Range match, be sure to move the staff back
to its vertical position if you are going to use your rifle again to shoot
shorter distances (i.e. BPCR Silhouette, Schuetzen, etc�).
By Darryl Hedges
Copyright� 2010 All Rights Reserved.