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SELECTABLE-APERTURE EYECUPS By Wayne McLerran
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Manufacturers & Suppliers:
Baldwin Sights (Steve Baldwin)
P.O. Box 971, Jones, OK 73049
Phone: (405) 399-2875
A well-known high-quality supplier of BPCR sights
Brownells Inc.
200 South Front Street, Montezuma, Iowa 50171
Phone: (800) 741-0015
Brownells sells Davide Pedersoli sights and Hadley-style adjustable
eyecup.
Buffalo Arms Co. (BACO)
600 Vermeer Court, Ponderay, ID 83852
Phone: (208) 263-6953
Buffalo Arms is the leading supplier of products for the BPCR reloader
and shooter. BACO sells the following brand of soule-type sights and
accessories: Kelley, Lee Shaver, Red River and Pedersoli.
Kelley Sights
High-quality sights for BPCRs. To check out the Kelley sight offerings
click on Kelley Sights above or Buffalo Arms Co. With the exception of
their Lyman-style eyecup Kelley sights are available for purchase from
Buffalo Arms.
Lee Shaver Gunsmithing
P.O. Box 570, 1020 Broadway, Lamar, MO 64759
Phone: (417) 682-3330
leeshaver74@yahoo.com
Lee supplies his own line of sights and accessories. Contact Lee
directly or go to Buffalo Arms Co. for his products.
Merit Corporation
P.O. Box 9044, Schenectady, NY 12309
Phone: (518) 346-1420
Merit manufactures adjustable aperture discs for shooting glasses and
rifle sights.
Montana Vintage Arms (MVA)
61 Andrea Drive, Belgrade, MT 59714
Daytime phone: (406) 388-4027, Evening phone: (406) 388-3405
MVA is a well-known high-quality supplier of BPCR sights and
accessories.
VTI Gun Parts (Pedersoli)
P.O. Box 509, Lakeville, CT 06039
Phone: (860) 435-8068
mail@vtigunparts.com
VTI is the USA based supplier of Davide Pedersoli sights, parts and
accessories. Pedersoli sights are also available for purchase from
Buffalo Arms (www.buffaloarms.com).
Wishing you great shooting,
Wayne

Last update: 8/17/20
Notes:
1) Selectable-aperture eyecups come with some rear sights. This
article assumes you already own or have decided on a rear tang sight
without a selectable-aperture eyecup. If not, than you may be
interested in the article titled Sight Suppliers for Black Powder
Cartridge Rifles.
2) In the following discussion “aperture” is defined the same as when
discussing optics or optical components, i.e. a hole or an opening
through which light travels.
There are five suppliers that I’m aware of for selectable-aperture
eyecups for black powder cartridge rifle tang sights. “Hadley-style”
eyecups are available from Montana Vintage Arms (MVA), Lee Shaver
Gunsmithing, Kelley Sights and Davide Pedersoli. MVA and Kelly offer
two eyecup versions, a standard size and a magnum or large size.
Baldwin Sights and Kelley Sights make “Lyman-style” selectable-
aperture eyecups.
MVA & Lee Shaver Standard Size Hadley:
The two most common Hadley-style standard eyecups purchased are
the Lee Shaver and MVA. I have used both. They are well made and
at first glance appear very similar to each other. They do suffer one
disadvantage which is discussed below under Other Considerations.
From the front the Lee Shaver and MVA look almost identical, but a
closer inspection will identify a few differences. As featured by
several suppliers, both the Shaver and MVA have a rubber ring around
the outer edge to help protect the shooters eyes and/or glasses due to
rifle recoil, and the stock comb when the sight is folded down. The
main differences are the layout and the size of the apertures. The
MVA standard eyecup apertures are laid out in reverse order
compared to the Shaver, which may or may not be important to a
shooter. In other words, rotating the MVA aperture disk clockwise
decreases the diameter of the selected aperture; rotating the Shaver
aperture-disk clockwise increases the aperture diameter. For what it’
s worth, the Shaver setup, which is common to most of the other
suppliers, seems more “natural” to me since it’s somewhat analogous
to other manual controls such as volume, speed or brightness for
example, which are normally increased by rotating clockwise.
Another difference not noted in the table is the Shaver is stamped L.
SHAVER on the front of the sight. The MVA has no markings at all.
The Shaver has a matt blued finish on the front and back. The MVA
has a matt blued finish on the front and a gloss blued finish on the
back. The Shaver inside cup surface is a little flatter (less concave)
than the MVA. The Shaver requires less effort to rotate the aperture
disk between detent positions. Considering all of the above and
assuming both are available in the thread size you need, I would
probably give the nod to the Lee Shaver version.
Kelley & Pedersoli Standard Size Hadley:
I have not used the Kelley or Pedersoli Hadley eyecups, but did discuss
the construction and features of the Kelley Hadley with the
manufacturer Jim Kelley. The Kelley design eliminates the problem
discussed below under Other Considerations.
Pedersoli’s Hadley is very similar to the MVA or Lee Shaver design but
has one less aperture selection. It has a metric M5 x 0.5 thread size to
match their rear sights. The diameter of the eyecup is not listed on
Pedersoli’s website but it’s approximately the same size as the MVA or
Lee Shaver. It also uses the back of the adjacent aperture for the
detent positions and, like the MVA standard Hadley, rotating the
aperture disk clockwise decreases the diameter of the selected
aperture.
MVA Montana Magnum & Kelley large size Hadley:
I have not used the MVA Montana Magnum or Kelley large eyecups,
although I have handled and installed the MVA Magnum on a rear
sight. At 1.95” in diameter, it is the largest of the Hadley-style
designs. It weighs a hefty 2.5oz and features a wide selection of
aperture sizes. It has a matt blued finish on the front and gloss blued
finish on the back. What I found interesting is the apertures are
arranged in the reverse order of MVA’s standard size Hadley. The size
may be too overwhelming for some shooters. By the way, it does not
have the problem discussed below in Other Considerations.
The Kelley Large Hadley is described very well in the table and is a
“petite” design when compared to the very large MVA Magnum. As
noted in the discussion on the standard size Hadley’s, the Kelley also
does not have the problem discussed below in Other Considerations.
Steve Baldwin & Kelley Lyman-Style:
If you like the looks of a traditional style eyecup and the smaller size is
visually pleasing, the Lyman-style may be the ideal solution as long as
your rear sight will accept 10-32 threads. The main difference
between the Baldwin and Kelley is the finish. The Baldwin has a matt
blued finish and the Kelley is color cased hardened. And be sure to
read the following discussion in Other Considerations that highlights
one key benefit to the Lyman-style design.
Note - The Kelley Lyman-style is the standard eyecup that comes with
a Kelley rear sight. It is not listed as a separate item on Buffalo Arms
website but it can be purchased directly from Kelley Sights.
Merit Adjustable-Aperture Eye Disc:
A discussion on multiple-aperture eyecups would not be complete
without touching on the Merit eye disc. Merit Corp. offers several
models of iris-type adjustable aperture eye discs, the most popular
being the #3 Adjustable Master Aperture eye disc with the 1.5”
neoprene light shield. As of this writing, due to the nontraditional
design, they are not approved for NRA sanctioned BPCR silhouette
matches. I do understand the Merit discs are permitted in BPCR long
range target matches. The aperture diameter is continuously
adjustable from .022” to .125” and it’s available with three shank
lengths and three thread sizes: 7/32-40 (12-40), 10-32, 10-40. The
disc with the light shield is available directly from Merit ($66.00) or
from Midway USA ($60.99).
Other Considerations:
If you’re struggling with making a decision between a Hadley-style or
Lyman-style eyecup, it’s obvious that one advantage of the Hadley-
style is the larger selection of aperture sizes. But the Lyman-style and
Kelley Hadley designs have an advantage over the Lee Shaver and MVA’
s standard Hadley’s that may not be obvious. The problem with the
design of some of the Hadley eyecups is the detent ball is in the same
radius as the apertures and snaps into the back of the adjacent
unselected aperture for the detent positions. Therefore, if the detent
ball is lubricated, oil can transfer to the apertures, making them a
dust/lint magnet. Although limited in aperture selection, the Lyman-
style design avoids the problem as does the Kelley Hadley design and
the MVA Montana Magnum. Look closely at the photos of the Hadley’s
and you’ll spot the reflection of the detent ball. The “Also Used for
Detent” column in the above table indicates which eyecup is at risk.
Another consideration and a possible negative of the Hadley-style can
occur when loosening the eyecup to adjust the elevation setting.
Depending on the location of the aperture disk, the disk can be
inadvertently and unknowingly rotated to a different aperture. The
Lyman-style prevents this from happening.
During your selection process, keep in mind that the threaded shank of
the eyecup must match the rear sight threads or the threads in the
elevator of the rear sight staff. If you already have a rear sight and
know the thread size the information in the following chart is most
likely not important. As noted, the most common thread size is 10-32,
but it’s certainly not a standard. Kurt Schinze provided much of the
data. I added a few details. But you know what they say about
assumptions, so don’t assume the thread sizes listed are accurate.
Double check the threads in your sight or contact the sight supplier
prior to ordering an eyecup.


