[Members] Sight Alignment
mike at designoutsource.net
Wed Jan 17 22:28:00 EST 2018
For all the members - sorry if this is a repost - I was answering from my
corporate email and I don't believe the technical description below was
allowed through due to the email not being subscribed.
One thing I forgot to add is the advantage of using the "Halo" on fixed
targets. For those of you unfamiliar with shooting techniques it is when you
minimize the outer white ring area shown in Julia's diagram. For stationary
targets you can minimize this gap through rear aperture diameter selection
relative to the eye relief desired. The optical refraction of the edges with
a minimal clearance will give you a "eclipse halo" that you can use to get
an easy automatic response to sight alignment that you would not otherwise
be able to discern with a larger gap. You will also get a refractive lensing
affect which depending on your eyesight, will have to be experimented with
to take advantage of. This technique can also be used for post & wing front
sights (peep or open rear sight), but to a lesser effect.
Here is the procedure we use for competition military rifles. This would
apply to any rifle equipped with peep & globe sights no matter what the
1) Determine stable mounting base conditions for front and rear sight
and that all base movement can be eliminated and is not subject to
structural deflection. This usually means direct mounting to the barrel as
far forward as to not affect muzzle "uncorking" pressure waves (usually 1"
minimum setback from muzzle is sufficient for a 22lr cartridge. Caveat: If
barrel harmonics are disturbed a "node" location may be required on the
barrel - or - subsequent barrel tuning using strategically placed weights
may be substituted after sight attachment. Rear sight should be attached on
the receiver portion of the rifle as far rearward as to allow for correct
view of front sight picture. In the case of the globe sight you have in the
PDF, if the globe sight has interchangeable inserts, then the correct sight
picture is obtained when the edge of the internal diameter of the globe
shroud is the maximum field of view diameter through the rear sight WHEN
POSITION AND PROPER CHEEK WELD ARE ESTABLISHED. This allows use of the
"halo" method of sighting.
2) Determine PROPER CHEEK WELD to the stock when in position to affect
NPA (natural point of aim). This has to be solid and repeatable! Next to
inconsistent trigger pull, this is the next greatest shot placement error
source. If the sight system has adjustable height on both the front and rear
sight, start with the rear sight to align it to the cheek weld position. Do
not make contact with the rear sight with any part of the position ( except
for very flexible membrane or "curtain" options if so desired. Then bring
the front sight height into the field of view to get the proper sight
picture. This may require several back and forth attempts on the two sight
heights - but critical - do not try to adjust your NPA/cheek weld to the
stock. If the rear sight cannot be adjusted for height, then a modification
or adjustment of the stock will be necessary to bring the NPA to the rear
sight. As an alternative, there are devices for measuring the NPA dimension
above the barrel centerline that will get you very close, but they may not
attach to your receiver depending on the rifle.
3) While you are doing this try to maintain both eyes open and a
relaxed vision. Do not stare through the sights for more than 8 seconds and
maintain breathing. If you find it takes longer, do it in steps with a long
slow close of both eyes for two breaths minimum. This will allow the eye
physiology to correct. Also do not attempt alignment with any direct light
source pointed at your eye (or reflecting off the sights in the 270 degree
arc area forward of your position. Try to use indirect and uniform lighting
in the rear quadrant during the procedure and place a neutral background in
the sight picture to maximize contrast. Your position should shade any rear
sight "splashback" to your eye.
4) Stable - sold - relaxed and natural sight picture. That is what you
are trying to achieve. Get rid of any strained neck positions and make sure
the cheek bone is properly in contact with the stock and can be brought into
position REPEATEDLY. After all this opening and closing the eyes should give
you the same sight picture time after time.
Feel free to contact me concerning these or any other firearm/ballistics
questions. Enjoy the build process!
Sr Director R&D
400 Young Court, Unit 5
Erie, CO 80516
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