TexasMac's Web Site
By Wayne McLerran
Updated 2/18/18

     Introduction
     Background
     Research Data on Current Suppliers
R.H.O. Instruments
Parson Scope Services
Montana Vintage Arms (MVA)
D.Z. Arms Scope
Leatherwood/Hi-Lux Optics
Buffalo Arms’ Setup - Leatherwood Scope & D.Z. Arms Mounts
Dixie Gun Works
     Considering Options
     Evaluation of the Leatherwood
     Unertl Mounts & De-clicking a Unertl
     D. Z. Arms Mounts
     Unertl Optical Co.
     J. W. Fecker Scopes
     Measuring Scope Magnification (Power)
     Short Malcolm-Style Scope Mounting Adapter Rail for Browning or
Winchester M1885 BPCR
     Mounting a Scope for Long Range Creedmoor Matches
     Recommendations
     In Closing & References


In my book, Browning M1885 Black Powder Cartridge Rifle, a section was
devoted to installing one of the long externally adjustable “tube type” period-
style scopes patterned from the classical Wm Malcolm design.  The discussion
did not include available scopes or mount options.  Prior to selecting a scope for
one of my rifles I spent a substantial amount of time researching the subject and
fully evaluated one scope during the process.  If you’ve considering mounting a
classic tube-style scope, either a modern day replica or an original, on a BPCR
you may find some value in the details of my research and findings.  For
additional help, check out Montana Vintage Arms (MVA) web site.  You’ll find
some good information applicable to mounting and adjusting an externally
adjustable scope.  MVA’s web site is listed below under the section titled
Research Data on Suppliers.

As of this writing I own one new Leatherwood brand replica scope which is
currently mounted on a caplock muzzle loader.  I also have three original
J.W. Fecker scopes which are mounted on a couple of Browning BPCRs and
a Steven’s Model 44 .22LR.


Since good quality Soule-style aperture rear tang sights and front spirit level
sights with interchangeable inserts are quite adequate and very accurate for
long range target or silhouette shooting, there’s little need for a rifle mounted
telescope unless one is required due to “aging eyes” or special circumstances.  
Unfortunately I have scar tissue in the central portion of the lens in my dominant
right eye, resulting from a childhood accident and subsequent operation.  The
scar tissue is not visible or a problem with normal vision, but obstructs the
central portion of the target image when enhanced by using an aperture rear sight
with a small peep hole.  Knowing a scope would solve the problem; I researched
the subject and started a full scale investigation of the available scopes and
mounts.  I intended to use the scope in NRA sanctioned silhouette matches;
therefore it had to meet the NRA's rifle silhouette rules, which I will go into
more detail on later.  The following information chronicles the process I went
through to select a scope for my Browning BPC rifles.  Hopefully it will provide
you some insight to help in your decision process.

Fundamentally, there are two scopes designs, internally adjustable and
externally adjustable.  Technology advancements have resulted in significant
and numerous improvements and features since rifle telescopes first appeared
in the mid to latter part of the 19th century.  Modern scopes mounted on most
hunting rifles are internally adjustable for windage and elevation.  They
typically are short in length with large diameter objective lenses made to gather
lots of light, offer variable power (magnification) adjustments, long eye relief
and many other high technology features.  The mounts are generally spaced 4” to
5” apart and only serve to rigidly hold the scope from moving and connect it to
the action and/or barrel.

Original or modern day versions of classical 19th century and early 20th century
scopes do not have internal adjustments for windage and elevation.  The mounts
not only must hold the scope rigid prior to firing the rifle, they serve two other
very important functions.  The rear mount must be adjustable for both windage
and elevation and both the front and rear mounts are generally designed to allow
the scope to slide forward, minimizing the effects of recoil on the scope and
possible shooter eye damage due to the relatively short eye relief of the design.  
The front mounts are also designed to allow the scope to pivot when the rear
mount is being adjusted for windage or elevation.  These scopes are relatively
long, generally 18” to 34” in length.

Externally adjustable rifle telescopes were introduced in the USA in the early
part of the 19th century.  A few companies are still manufacturing updated
versions for the BPCR shooter.  Most are either patterned after the classic
William Malcolm design or at least heavily influenced by the old Malcolm
scopes.  William Malcolm, who previously worked for a telescope manufacturer,
began production of an achromatic lens and rifle telescope in 1855.  Two years
later The Malcolm Rifle Telescope Manufacturing Company was established in
Syracuse, NY.  Malcolm scopes were used in the Civil War by sharpshooters.
Although there were earlier rifle telescope manufacturers, Malcolm’s scope
design is the one most referenced by current manufactures.  A ladder-type rear
mount he introduced much later is also used as the design basis for several
current suppliers.

Moving forward, the most well known early 20th century supplier is Unertl,
followed by Lyman, Winchester, and possibly Stevens.  Less known are J. W.
Fecker and R. A. Litschert.  Several configurations included large diameter
tube bodies, large objective lenses and high power options.  Although no longer
produced, many of these scopes are still being used and can provide very good
service for long range silhouette and target competition.  In fact many silhouette
shooters prefer the older scopes to those available from current manufacturers,
which can be more costly and may not offer adequate mounts in some cases.  Of
course the older models and mounts must meet the NRA rifle silhouette rules.

With the recent addition of a very nice scope manufactured by D.Z. Arms, the
list of current USA companies manufacturing externally adjustable scopes
now stands at three.  Montana Vintage Arms (MVA) and D.Z. Arms are the only
USA manufacturers I'm aware of.  R.H.O. Instruments, Romano Rifle Co. and
Parsons Scope Service no longer make scopes.  There are also a couple of
brands imported into the USA by Leatherwood / Hi-Lux Optics and Dixie Gun

All the scopes in the following discussions are in full compliance with the
features and dimensional requirements stated in the NRA’s rifle silhouette
rules.  The same cannot be said for some of the mounts.  There are no power
limitations on BPCR silhouette scopes, but there are physical design
limitations.  As of this writing the NRA says that scopes must meet the same
requirements as BPC rifles.  In other words, originally made in the United
States prior to 1896 and being typical of the era.  Replicas thereof, regardless
of origin of manufacture, are permitted.  The current NRA rules also include
the following stipulations:
1)   Maximum weight (rifle) weight with scope – 15 pounds.
2)   No length or power limitation.  Scope tube body to be ¾” or less in
diameter and any ocular or objective lenses, adjusting or assembly rings to be
less than 1” in diameter.
3)   No internal adjustments for windage or elevation.
4)   Mounts are to be of a traditional style of the period, and contain the
windage and elevation adjustments for the scope in either, or both, the front or
rear mounts.  No click adjustments in the mount.  Either dove tail mounting or
scope block mounting is allowed.  The current NRA Rifle Silhouette Rules
handbook further states that, Original scope mounts of either the Cataract or
Malcolm style or variations thereof, or replicas or derivatives of either style, are
allowed provided the replica or derivative conforms to the criteria of rule 4)
5)   Cheek pieces may be used and may be of any height.

Research Data on Current Suppliers
(Product Offerings, Features & Comments)

Please note that some of the following data may be a few years old.  In some
cases I’ve included an update date.  Therefore, prior to making a final
decision I recommend you check out the current product offerings of the

R.H.O. Instruments
In 2010, Randy Oates owner of R.H.O., decided to get out of the scope
manufacturing business.  I’m including the details here since there’s a good
chance of finding a used R.H.O. scope.
•        Magnification: 6X.
•        Field of view at 100 yards: 10 feet.
•        Telescope weight: 13 oz.; mounts: 6 oz.
•        Reticle: plain fine crosshair only.
•        Achromatic objective lens, for improved image clarity.
•        Eyepiece is adjustable for focus.
•        Eye relief: approximately 4".
•        Vernier elevation scale on rear mount is graduated in 2 minute
increments. Total adjustment available: 180 minutes.
•        Windage scale on front mount is graduated in 3 minute increments.
Total adjustment: 36 minutes, 18 minutes each side of center zero.
•        All scales are machine cut, and then nicely numbered on a restored
1943 Gorton Pantograph Engraving Machine.
•        Mounts install in the dovetail slots in your barrel.
•        Mounts are available with standard dovetail dimensions made to fit
Shiloh or C. Sharps factory dovetail slots.
•        All mount parts are machined from solid steel stock. No stampings or
castings are used. Telescope is 3/4" diameter 4130 drawn steel tubing.
Eyepiece and dust caps are machined from solid brass.
•        All parts precisely machined, fitted, polished, and blued.
•        Were available only for rifles with 30", 32" or 34" barrels.

Additional comments:
        Since R.H.O. scopes are rigidly mounted and are not allowed to slide
under recoil, I discussed the long-term durability with Owner, Randy Oates.  
He said he has not had a scope returned due to a recoil related problem
        Front and rear mounts use dovetails, which must be cut if not available.
        Mounts must be drifted out of the dovetail to use on another rifle.
        Scopes are not hermetically sealed but do use O-rings and silicon
grease to eliminate moisture problems.
        Reticle is a fine-wire design with one vertical wire and two horizontal
wires (one in the center and one approximately 18 minutes lower)
        Brass eyepiece
Parallax adjustment is not available.  9/6/08 – Randy Oates replied to my
question to him on parallax, “… the telescopes are not adjustable for parallax.  
However, due to the quite long focal lengths of the lenses used in the telescopes,
parallax is not much of an issue.  The telescopes are zeroed for parallax at 200
yards, and there will be essentially no parallax at distances further than this.  At
say, 100 yards a small amount of parallax may be observed, but this will amount
to no more than approx 1/8’’ total movement of the crosshairs.  At 50 yards
observable parallax will be about ¼’’.  In practice, actual effective parallax will
be even less since the relatively small exit pupil diameter of this type of
telescope tends to keep the eye well centered in the image (field of view).  If a
person wants to use one of the telescopes at a very short distance all the time,
say 25 or 50 yards, I can adjust the parallax to zero at this distance, but there
will then be some parallax at longer distances.  Regards, Randy Oates.

Parsons Scope Service, 513-867-0820
Note: Parsons’ no longer manufacturers scopes, but does repair most brands
of vintage external adjustable scopes or modern copies thereof.  Parson's
included here since there’s a good chance of finding a used Parsons made
Parsons says that MVA essentially copied their scope and mount system.
•        6X power, ¾” blued steel tube
•        Eye relief: 2” (which works fine due to the fact that scope slides under
•        Scopes are not hermetically sealed but do use O-rings and silicon
grease to eliminate moisture problems.
•        Can use screw-on or dovetail blocks.  Lyman/Unertl type screw-on
blocks require drilling and tapping the barrel. Parsons does not supply the
blocks, but refers buyer to Steve Earl Products (781-585-3929).
•        Adjustable objective for parallax adjustment.
•        Front and rear mounts are very high quality and allow the scope to
slide under recoil.  Scope has a battery stop to reset back to shooting position.  
The front mount is designed to work with a Pope-style rib, which is on the
bottom of the front portion of the scope and insures the scope does not rotate as
it moves fore and aft.
•        Can be easily moved to another rifle that has correct mounting blocks.
•        Reticle is fine-wire crosshair.  A custom 7-dot reticle, similar to MVA’s
Mil-Dot Reticle, is available for an additional $100)
•        Six tube lengths (24”, 26”, 28”, 30”, 32”, 34”)
•        Last retail pricing was around $900.

Montana Vintage Arms (MVA), 406-388-4027
MVA standard scopes
•        Magnification: 6X
•        Range adjustment: 10 yards to infinity
•        Parallax adjustable using adjustable objective
•        Reticle adjustment for Level
•        Field of view @ 100 yards: 10 feet
•        Exterior finish: blued steel
•        Pope style rib allows the scope to slide under recoil
•        A stop is provided to return the scope to the battery position
•        Malcolm style mounts (blued steel) , with front and rear windage
•        Screw-on covers for both ends
•        Clear objective cover lens to protect lenses

Additional Comments:
        Eye relief: 2” (works fine due to the fact that scope slides under recoil)
        Scopes are not hermetically sealed but do use O-rings and silicon grease
to eliminate moisture problems.  MVA admitted that if the scopes get extremely
wet for an extended amount of time, as in a heavy rain, it’s possible for some
moisture to work its way inside.
        Choice of screw-on or dovetail blocks.  Lyman/Unertl type screw-on
blocks require drilling and tapping the barrel.
        Front and rear mounts are very high quality and allow the scope to
slide under recoil.  Scope has a battery stop to reset back to shooting position.  
The front mount is designed to work with a Pope-style rib, which is on the
bottom of the front portion of the scope and insures the scope does not rotate as
it moves fore and aft.
        Can be easily moved to another rifle that has correct mounting blocks.
        Several reticle styles, which are acid etched on a glass plate, are
available at no additional charge.
        Four scope lengths and choice of silhouette or schuetzen mounts.
        Great phone customer service concerning sales and answering technical
        Scopes are only available direct from MVA.  No retailer or Federal
Firearm License (FFL) discounts are available.

MVA’s new B-Series scopes (updated 2/20/14)
MVA recently introduced an “economical” series of scopes called the B-Series.  
As of this writing there’s no information on their web site.  I spoke with a factory
representative for the following information:
•        The blued steel scopes are available in three power versions: 3x (B3), 4x
(B4) & 5x (B5), and are 13.5” to 15.5” long depending on the power.
•        They come with your choice of reticles, mounts and scope blocks.
•        The scopes do not have a Pope-style rail, but do feature a longitudinal
indentation to provide the sliding function while preventing rotation.  The
front mount uses a spring loaded plunger that rides or tracks in the indentation to
keep the scope from rotating.  With each shot the scope slides forward due to
recoil and must be returned to “battery” prior to the next shot.
•        Additional features include a reticle level adjustment, parallax adjustment
and focus from 10 yards to infinity.
•        The windage and elevation adjustments on the #1 or #2 rear mounts are
non-click-style.  The #1 mount has scales on top of the turret heads that give
a rough 1.5 MOA of adjustment resolution.
•        The #2 mount is larger for more windage and elevation adjustment and has
finer micrometer-style scales on the side of the turret and barrel for
approximately 0.5 MOA of adjustment resolution.

Based on the above noted features, the #1 mounts should be an excellent
solution for general shooting and hunting.  The #2 mounts would be necessary
for silhouette competition with targets set at various extended ranges, requiring
precise and repeatable windage and elevation adjustments.

By the way, a MVA B-Series scope with #1 mounts is similar to the
Leatherwood Malcolm scope with standard Leatherwood mounts.  The
differences are that the Leatherwood is 6-power, does not slide under recoil,
does not have a parallax adjustment, and the Leatherwood mounts are not
manufacture to the high quality standards of the MVA mounts.

D.Z. Arms Scope, 405-691-1215
Made in the USA, the scope was introduced in late March 2014.  It can be
purchased separately or with a “scope-ready” package.  For additional
information on the mounts see the discussion titled D.Z Arms Mounts further on
in this article.
•        Magnification: 8X
•        Length: 20”
•        Construction: ¾” blued steel tube
•        Screw on scope cover for both ends
•        Cross-hairs are acid etched on a glass plate
•        Parallax adjustable using adjustable objective
•        Add-on rib and scope stop is available to allow the scope to slide
under recoil
•        Additional “scope-ready” package includes the following: D.Z. Arms
mounts, add-on rib, 2 mounting bases (blocks)

Leatherwood / Hi-Lux Optics, 310-257-8142
Leatherwood scopes are imported into the USA and distributed to firearm
dealers and retailers by Hi-Lux Optics.  The scopes are available from
several companies including Buffalo Arms 208-263-6953, Dixie Gun Works
713-885-0700, Cimarron Firearms 830-997-9090, Numrich Gun Parts 845-679-
2417.  Davide Pedersoli & C. is the European retailer.  With a FFL license,
wholesale or reduced pricing is possible directly from Hi-Lux Inc. or possibly
from some of the retailers.
Note – I fully evaluated the Leatherwood 18” long 6 power scope.  
Additional details and comments are provided later.

Leatherwood 30.5” (long) scope:
Image is reported to be very clear and sharp, better than MVA or Parsons
and most likely the preferred scope for hunting, especially in wet conditions.  
These comments also apply to the 18” 6X version.
•        6X power, ¾” blued steel tube
•        Eye relief: approx. 4.0” (long scope)
•        Waterproof – hermetically sealed and nitrogen filled.  No chance of
moisture getting inside.
•        Plain fine-wire crosshair reticle (No option for different reticles)
•        Will fit 26” to 34” barrels on single-shot rifles, depending on extension
tube used (3”, 5”, 7” & 9”).  The 5” extension tube is used on 30” barrels.
•        Front and rear mounts are not sufficient quality for competition.
•        Shinny Brass eyepiece and crosshair ring.  (Using an appropriate bluing
solution the brass can be darkened)
•        Parallax adjustment is not available.
•        With the normal mounts the scope is rigidly mounted and is not allowed
to slide under recoil.
•        A Sliding Mount Accessory (SLDMT) is available, which allows the
scope to slide under recoil.  One end of the SLDMT attaches to the rear
mount (replaces the rear mount scope clamp).  The other end clamps on the
scope and slides on the rail.
•        A Sliding Lock Ring (SLR) is also available to allow the scope to slide
an inch or so under recoil but not rotate.  The SLR replaces the standard front
locking ring.
•        Standard front and rear mounts requires a dovetail, but with the heavy
duty base adapter the rear mount is secured with screws requiring drilling and
tapping the barrel.

Leatherwood 17” & 18” (short) Scopes:
•        17” - 3X power, 18” - 6X power, both are ¾” blued steel tube
•        Eye relief: approx. 4.5”
•        Waterproof – hermetically sealed and nitrogen filled.  No chance of
moisture getting inside.
•        Plain fine-wire crosshair reticle (No option for different reticles)
•        Normally the scope is rigidly mounted - not allowed to slide under recoil.
•        Leatherwood offers a Scope Sliding Lock Ring (17SLR ) similar to the
one for the long scope, but works with the front mount on either the 17” or 18”
scopes.  It rigidly clamps to the scope body and provides an under-tube bar
that slides in a notch in the front ring, allowing the scope to slide under recoil.
•        Rear micrometer mount looks like a copy of an original Lyman small
game scope mount (no click adjustment & a locking ring to lock the adjustment
knobs).  Due to the coarse markings located only on the top of the knob they
are not adequate for the precision adjustments required for long range
competitive shooting.
•        Parallax adjustment is not available.

Dixie Gun Works, 713-885-0700
Dixie sells the Leatherwood scope (EP0050) and attachments.  Heavy Duty
Scope Base Adapter (EP0027) and Scope Locking Clamp (EP0028), also
known as the Recoil Ring, are sold separately; as are the 3”, 5”, 7” & 9”
extension tubes and a few other accessories for the Leatherwood.  Dixie also
sells the following much cheaper scopes.
•        4X Power
•        Eye relief: 3”
•        ¾” brass tube
•        15mm brass eyepiece
•        Two scope lengths, 18.5” (EP0006), 32.5” (EP0008)
•        Very simple brass mounts

Considering Options
At this point in my quest I was still unsure as to what direction to go.  The costs
of the new scopes were certainly higher than expected and I had yet to resolve
spending in the range of $900 to over $1000 for one from MVA or D.Z. Arms.  
After discussing some of the pros and cons and my indecision online with
several scope owners I contacted an experienced BPCR scope shooter and highly
regarded gunsmith.  In his opinion MVA mounts are good but have some
potential for backlash / hysterias.  Therefore he suggested I locate a good set
of used Winchester A5 or Lyman 5A mounts and purchase the scope separately.  
Winchester A5 mounts are referred to as the “grasshopper” mount in reference to
the under tube spring.  Both the Lyman and Winchester, if they are the clicked
version, could be easily de-clicked to make them NRA legal.  He further
commented that Unertl mounts are the best of all, but most are not NRA legal
due to having click adjustments.  By the way, I did check with MVA and found
the following on their web site.  Concerning backlash MVA says, “You may
notice very slight backlash in the threaded adjustments, but this is necessary for
any threads to ensure that they do not bind up during operation.  As long as any
adjustments made are in the same direction of rotation of the screw, there will be
no correction required for the backlash.”

All of these precision high-quality rear mounts, which feature precise and
repeatable adjustments, are generally referred to as “micrometer-style” mounts.  
In contrast to MVA’s ladder-type or Malcolm-style, the Unertl or Cataract-style
are sometimes referred to as cage-type mounts; cage-type being used in
reference to their shape.  The basic design is attributed to the Cataract Tool &
Optical Company, which was later improved on by the J. W. Fecker Company.  
Unertl essentially copied the J. W. Fecker Company improved design.  The
cataract-style mounts are spring loaded to eliminate the possibility of backlash
or hysterias in the adjustments.

Only after further research did I become aware of the Unertl-like very high
quality J.W. Fecker mounts, which can be found without click adjustments.  I
also ran across an extremely good deal on a Unertl rear mount I could not pass
up.  It's the standard base type, which will be discusses in more detail later.  The
spring and plunger were missing and the mount was click adjustable, but I
quickly figured out how to “de-clicked” it to comply with NRA rifle silhouette
rules and eventually purchased replacement parts from Unertl, which is still in
business although no longer selling mounts.  If you’re interested in a Unertl
mount, I’ve included much more data later on including the different style of
mount bases and the simple technique I used to disable the clicking adjustment.

Now, this brings me back to the Leatherwood scopes.  I had heard good things
about the quality of the Leatherwood scopes but not the mounts.  The
Leatherwood Wm Malcolm scopes are certainly much cheaper than those from
MVA or D.Z Arms.   So, being an opportunist at heart, I figured the odds were
good that I could save several hundred dollars by matching up a Leatherwood
with the Unertl mounts.  After checking and performing a few calculations, it
became clear that the 30.5” Leatherwood scope was too long to use with the
limited adjustment range of the Unertl rear mount.  But the shorter 18” scope
was ideal and offered more than sufficient range.

I will not go into all the details of the calculations here.  As mentioned earlier, I
devoted a chapter in my book to mounting an externally adjustable scope on a
BPCR, including the necessary calculations.  If you're interested you can order a
copy from this web site.  But I will discuss the subject a bit more.  The same
formula for adjusting iron sights can be used with an externally adjustable
scope.  Therefore, if one knows the minute-of-angle (MOA) value required to
adjust the scope from say 200 meters to 500 meters (the overall target distances
for silhouette competition), one should easily be able to determine if the rear
mount has sufficient adjustment range.

So let’s use the formula, which in one form is: MOA adjustment range = mount
adjustment range (inches) x 3600 / mount spacing (inches).  When reviewing my
shooting notes I found that, for 200 to 500 meters, a realistic adjustment value
for a .45-70 or .40-65 caliber rifle is 55 MOA.  Also knowing that the maximum
adjustable range of the Unertl rear mount is 0.250”, let’s use 7.2” for the scope
mount spacing, which is common for 18” to 23” long scopes.  So, after
“plugging the values in the formula, the answer is 125 MOA, which is more than
sufficient and allows a comfortable margin.  Now I had to find a Unertl front
mount and a scope to fit.  I decided to order an 18” Leatherwood scope and
evaluate it.

But before moving on to a discussion on evaluating the Leatherwood, I’d like to
cover another example of mount-to-scope fit or compatibility.  Let’s determine if
the Unertl rear mount will work with a 30” long scope.  Using the same formula
and the same mount adjustable range (0.250”), let’s now use a scope mount
spacing of 17”, which is typical when mounting a 30” long scope.  The answer is
a total adjustment range of only 53 MOA, which is not sufficient.  Now keep this
example in mind for a later discussion on mounts available from D. Z. Arms.

Evaluation of the Leatherwood
(Model # M634181)

Initial evaluation prior to firing:
Scope specifications: 18” long, ¾” tube diameter, 6X power, 17mm objective,
12’ field of view at 100 yds, 4.5” eye relief, weight 18 oz (see more on this
below), 5.8mm exit pupil, no parallax adjustment.  All air-glass optic surfaces
are fully multi-coated for maximum light transmission.  Parallax is set for 10’ to
infinity.  The reticle is a fine crosshair.  The scope is shockproof,waterproof and
nitrogen filled.

Opening the shipping box I found the following:
1)   The scope, with mounts installed, metal protective end caps and scope
blocks; came double sealed in plastic bags (sealed in a clear plastic bag
inside a sealed bubble wrap bag).  Also included are an 8-page instruction
manual and a cheap, small square piece of felt cloth to clean lenses.
2)   The scope, end caps, mounts and scope blocks were covered with
lightweight oil.
3)   Only markings on the scope (Wm MALCOLM over 6X) are located 1&1/4”
in front of the eyepiece locking ring.

To remove the front and rear mounts from the scope required 1st removing
the adjustable eyepiece and locking ring.  The scope has as inner sealed glass
lens in front of the eyepiece to maintain the hermetic seal and allow eyepiece
adjustment and removal.

I weighed everything on a very accurate postage scale.  The results were:
1)   Scope, end caps, mounts and blocks (no block screws) – 19.6 oz
(1 lb 3.6 oz)
2)   Scope without mounts, end caps or blocks – 12.8 oz
3)   Both protective end caps – 2 oz

The exterior surface finish of the all-metal (possibly steel) scope tube, objective
lens housing, eyepiece and eyepiece locking ring are acceptable.  The blued
metal finish has a few very light machining marks in a couple of areas.  The
adjustable eyepiece and end cap threads are rough but functional.  All were
coated with a light oil, including the inside threads for the end caps, which were
very close to the objective and ocular (eyepiece) lenses.  Knowing what oil can
do to scope lenses, this concerned me.  If the scope was not nitrogen filled and
hermetically sealed I would have been very concerned due to the high
probability of oil leaching into the inner workings of the scope.  To eliminate the
possibility of oil getting on the lenses, I gently removed all the oils in the threads
with Q-tips and solvent, being cautious not to get solvent on the lenses.  Surface
oils were removed from the scope exterior surfaces withthe cheap lens cloth.


Front mount & locking ring:
Mount is functional but not well finished.  Blued metal surfaces are rough
with lots of casting and machining marks.  The mount is designed with a locking
screw to attach to a standard 60-degree dovetail block.  The separate locking
ring works with the front mount to prevent the scope from rotating or moving
fore and aft but allows the scope to pivot for windage and elevation adjustments.
Note – I did purchase a sliding lock ring (Part # 17SLR - sold separately),
which allows the scope to slide out of battery under recoil but keeps it from
rotating.  It replaces the standard lock ring.  The construction and metal
surfaces are similar to the front mount.

Rear cage-type mount with windage and elevation adjustments:
Mount is functional but not well finished.  Blued metal surfaces are rough
with lots of casting and machining marks.  The scope contact surfaces of the
turret knobs are very rough and will definitely scratch or score the scope surface
during adjustments.  One complete turn of the knobs provides 0.020” of scope
adjustment.  The mount is designed with a locking screw to attach to a standard
60-degree dovetail block.  To call it a micrometer-type mount would be a
misnomer since there are no micrometer-type scales on the turret knob housings
to use as a reference.  In other words, if the turret knobs are turned and the
number of rotations is not noted, it would be almost impossible to return the
knob to a previous setting.  Clearly, at least in my mind, the mounts are made for
recreational shooting or hunting, where the scope is adjusted for a specific
distance and the knobs locked in place with the locking rings.  Even in this case I
would definitely file and polish the ends of the turret knobs to eliminate or
reduce scope surface damage.

Dovetail style mounting blocks:
The two identical standard 60-degree type dovetail mounting blocks are
reasonably well machined, blued and finished.  The blocks are ½” (actually
0.490”) wide on top with 60-degree shoulders, and are 1.285” long.  The two
mounting holes in each block are spaced 14.2mm (0.559”) apart and will accept
standard 6-48 or similar size screws.  The blocks that came with my scope are
designed with a half moon slot on one side and a Posa slot on the opposite side
to also fit Unertl, Fecker or similar type mounts.  I understand that blocks
shipped with more recent scopes only have the standard half moon slot on one


Evaluation under firing conditions:
After additional considerations I decided to mount the Leatherwood on a 50
caliber caplock muzzleloader I used for local competition many years ago and
plan on using for whitetail deer hunting.  It’s a customized version of the
Thompson Center Hawken rifle and my aged eyes have been having a hard time
focusing in on the front sight.  Another reason for mounting it on the TC was to
try it out prior to possibly using it on one of my Browning BPCRs.  Following is
a photo of the Leatherwood mounted on the custom Thompson Center.
The TC flat top barrel was drilled and tapped for mount spacing of 7.2”.  The
Leatherwood scope blocks worked fine with 6x48 screws.  The front mount
setup allowed the scope to pivot sufficiently for windage and elevation
adjustments, but held the scope from sliding under recoil.  After 50 or so rounds
and adjusting the scope, I must say I was impressed and quite satisfied with the
whole setup as a hunting scope setup.  The scope image was very bright and
crisp with no distortions, and the plain crosshairs were sharp.  The front and rear
Leatherwood mounts worked great.  The rear windage and elevation adjustments
worked fine and stayed in place.  Once I had the scope centered I locked the rear
mount elevation and windage adjustments with the knurled finger-locking nut
and nothing moved during subsequent shots.

By the way, the load was 90 grains of Goex 3X behind a spit-patched 177 grain
round ball.  The average muzzle velocity was 1856 fps.  The rifle & scope
weigh 9 lb 11 oz.  All the shooting was at 50 yds and I plan another trip to set it
dead on at 75 yds.  Anything past 75 yds would be stretching it for taking a
whitetail due to the drop off in muzzle energy with round ball ammo.  And I did
not notice any parallax affects or problems at 50 yds, but I will evaluate parallax
out to much longer distances at the next opportunity.  Oh, and I did check the
short focus distance.  The target image did not clear up until around 40 to 45
yards.  Since there's no parallax or focus adjustment it's usable for less than 45
yards but the image will progressively get worse as the distance is reduced.  It
was very clear at 50 yards and greater distances.

Following is a photo of an 18” Leatherwood mounted on a recent Winchester
M1885 Limited Series rifle, which is identical to the Browning M1885
Traditional Hunter.  The existing factory dovetail for the rear barrel sight was
used as were the existing factory holes in the receiver.

Unertl Mounts & De-clicking a Unertl

First, allow me to make the following very clear.  I’m no expert on Unertl
scopes or mounts.  I don’t know if all Unertl turret mount adjustments are
similar, but the one I have was easy to de-click to make it NRA silhouette
legal.  See the photo below of the disassembled ¾” mount.  The spring and
plunger pictured to the left of the mount reside in the lower left cavity of the
mount.  They apply the necessary force to hold the scope body firmly against
the two adjustable turrets.  The spring and plunger were missing when I bid and
won the mount on eBay.  I eventually obtained them after finding that Unertl is
still in business and selling some replacement parts.  But I’m getting off the
subject of de-clicking the mount.

A right-angle pin is installed into a hole in the bottom end of each turret
assembly.  When functioning as originally designed, as the knob and threaded
section of the turret are rotated during adjustments, the pin holds the bottom end
from turning while sliding up and down as necessary in a slot in the mount
housing.  Through the center of the threaded section, the bottom end of the turret
assembly is directly connected to a thin round flat disk resting on top of the
knob.  Since, due to the right-angle pin, the bottom end of the turret assembly
cannot rotate, the flat disk cannot rotate.  The flat disk has a small “dimple”
close to the edge.  When the knob is rotated under it the dimple snaps over
notches formed in the top of the knob.  Removing the right angle pin de-clicks
the turret.  It’s that simple.  Just completely unscrew and remove the turrets.  
Then grab the right angle pin with a pair of pliers and pull it out while gently
rotating it back and forth.  In my case, one came out easily.  The other one was
very tight.  If it breaks off and you have no plans for using the click feature, just
file off any remaining rough edges.  To control the tension on the now de-
clicked mount, tighten the screw in the upper right hand corner.  Another
method that reportedly works is to clean the turret threads of oil and apply a
drop of linseed oil or some rosin.  I have not tried either so can’t comment, but
it sounds reasonable to me.
Unertl cage-style micrometer rear mounts come in two variations, a standard
base design and a Posa base design.  The one shown disassembled in the above
photo has a “standard” base.  Most Unertl mounts you see are the standard base
design.  The two photos below are of a complete set of front and rear mounts
with standard bases.  These are for a larger diameter scope, but the design is
basically the same for a ¾” scope.  Tape is holding the spring and plunger from
popping out.  Also evident is the notch in the front mount plunger, which slides
over and aligns itself on the Pope-style rail or rib on the front top of the scope.  
The rib serves to hold the scope in rotational alignment while also allowing it to
slide due to recoil.

Unertl mounts with standard bases require unique matching blocks, which screw-
mount onto the top of the action and/or rifle barrel.  It’s not visible in the photos,
but the end of the base thumb-screw is cup or concave shaped to fit a matching
bump or convex shape on the scope block.  Some refer to the block as having a
crescent cut to accept the standard thumb screw.  In contrast to the Posa-base
mounts detailed below, standard style Unertl mounts only clamp on one side of
the dovetail and in the convex bump on the other side.  The convex bump and
matching thumb screw also ensures the mount does not slide on the block,
maintaining rigid center-to-center mount spacing.  Following the two standard
base mount photos below is a photo of a standard block.
Another version of the Unertl mounts has, what’s referred to as, a Posa base.  
Below is a photo of a Unertl rear mount with a Posa base.  Another photo of
front and rear Posa mounts can be seen in the following discussion on D. Z.
Arms mounts.  Although the Posa base mount is very similar to the standard
base mounts detailed above, notice the base is split, which allows the mount to
tightly clamp and align on both sides of the dovetail.  Hence Posa mounts are
more rigid and are typically only used with larger scopes to handle the heavier
recoil assuming a recoil spring is used (see note below).  Posa base mounts
require unique matching blocks.  The end of the base thumb screw is flat
bottomed to fit into a flat bottom notch on the scope blocks.  The notch only
serves to locate the mounts fore and aft to hold center-to-center mount spacing
Note – If a recoil spring is not used than the split-base design of the Posa mount
is not utilized to its fullest extent since the mounts are only subjected to the
frictional forces of the sliding scope when the rifle recoils.  If a recoil spring is
used than the front mount must absorb the spring energy due to recoil and
especially when the spring returns the scope to battery.  Therefore it’s more
important that the front mount is a Posa design than the rear mount although for
symmetry and esthetics both mounts are usually Posa style.
Now, let’s digress back to the earlier example in the section titled Considering
Options where the scope mounting formula indicated the Unertl mount did not
have sufficient adjustment range for a 30” long scope.  Enter a company named
D. Z. Arms, which has come up with a solution, a very high quality modified
version of Unertl’s ¾” mounts.  Dan Zimmerman, the owner and the “D. Z.” in
D. Z. Arms, informed me that Sean Moore, an employee of D. Z Arms, deserves
all the credit.  The mounts feature an extended elevation adjustment range for
long scopes.  They are a little taller in the vertical direction and have a longer
elevation turret, resulting in an additional 0.200” of vertical adjustable range
(total of 0.450” of adjustment).  The end of the windage turret has also been
redesigned slightly to allow for the additional range.  The mounts do not have
click adjustment and therefore meet the NRA rifle silhouette rules.  They make
mounting a 30” or 34” scope possible while benefiting from the backlash free
design of the original Unertl mounts.  If spaced 17” apart the mounts provide
approximately 95 MOA of elevation adjustment.  The photo below displays the
redesigned mounts to the left of an original Unertl rear mount.  By the way, note
that the mounts in the photo are designed with a Posa-style split base, but
standard non-split mounts are also available.  And if you’re wondering how
these mounts work with a MVA scope, which has the Pope-style rib on the
bottom, the not so obvious answer, at least to me, is to just turn the MVA scope
over.  I felt like a real idiot after asking Dan the same question and receiving his
response.  He’s probably still laughing.  The company contact information is:
web site,
http://www.dzhepburn.com/ email, dan@hepman.com; phone, 405-
                                            Unertl Optical Co.
                               (A little history and recent status)

Although the earlier discussion on Unertl focused primarily on their mounts, I
also mentioned that Unertl is the most well known supplier of early 20th century
externally adjustable scopes.  Unertl scopes are considered by many to be top of
the line and generally command a price premium when one comes up for sale.  
Although manufacturing of externally adjustable scopes ceased many years ago,
Unertl is still in business.  Following is a short overview of the current company.

Formerly known as John Unertl Optical Company, Unertl was founded in 1934
and was originally based in Mars, Pennsylvania.  The current Unertl Optical
Company, Inc. continues to manufacture and market products under the brand
name Unertl.  The product line includes telescopes, mirror mounts, riflescopes;
specialized sights and optics for law enforcement agencies and armed service

October of 2000
I understand that 21st Century (owned by John Unertl Junior and Rocky Green)
purchased the assets, patents and the Unertl trademark.

-        Rocky Green is now the sole owner of the company.
-        Headquarters moved to 2900 South Highland Dr., Las Vegas, NV 89109,
702-369-4092.  The Las Vegas location develops and works on night sights and
military optics.
-        There’s still a very small office in Mars, PA, 16046 (P.O. Box 895 –
Staffed by Freda Shaw, 724-816-2813).  If you call Freda she will most likely
refer you to either the Las Vegas or Fairborn operations.

A small operation is now located at 17 S. Hampton Rd., PO Box 234,
Donnelsville, OH 45319-0234, staffed by Aaron Davis, a long-term Unertl
employee.  Aaron repairs and reconditions externally adjustable Unertl scopes.  
He can be reached at 937-631-2854 or via email at
Some parts are also available for sale.  If you need parts and/or repairs, this is
the Unertl guy you need to contact.

Before closing out this section on Unertl, I included three photos of a Unertl ¾”
Small Game Scope, which is, as far as I know, the only Unertl scope that meets
the NRA’s rules for silhouette competition.  The mounts would need to be de-
clicked to make them NRA legal.  The Small Game Scope was originally
manufactured in 3X, 4X or 6X power.  It’s 18" long and weighs approximately16
oz. Both the objective and ocular lenses are 3/4" diameter.  The magnification of
the scope in the photos is 6X.  If you look closely, the Pope-style rib or rail
extends along the top front section of the scope under the spring and front mount,
and ends just behind the objective lens bell housing.  The rib serves to hold the
scope in rotational alignment while also allowing it to slide under recoil.  The rib
slides in a notch in the front mount plunger.  Revisit the earlier photos of the
front mounts and you’ll see one clearly displaying the notch.  The large spring
assembly around the front end of the scope is appropriately referred to as a
recoil spring and is meant to absorb recoil and automatically return or slide the
scope back to “battery” position after the rifle is fired.  Since, per my
understanding, the recoil spring is not allowed by the NRA, it can be easily
removed and the scope slid back to the battery position by hand after each shot.

Another feature of the Unertl Small Game Scope is the parallax/focus
adjustment, which is located at the back end of the rib.  It consists of a screw
and washer on each side of the scope body.  Focus and parallax is adjusted by
loosening both screws slightly then sliding the screws back and forth a small
amount while looking through the scope to check parallax and focus.  The
screws hold the internal erector lens in place.  The normal procedure is to adjust
parallax for the most common shooting distance and leave it along.  This works
fine for a small game rifle used at typical hunting distances, but may not be
acceptable for long-range silhouette competition where banks of targets set from
200 to 500 meters.  With that said, I do know of silhouette shooters that do not
adjust parallax during an entire match.
                                           J. W. Fecker Scopes

As noted earlier, Unertl is the most well-know 20th century externally adjustable
scope manufacturer.  Also mentioned were Winchester, Lyman, Stevens and
Litschert.  But scope historians and knowledgeable shooters are also well aware
of scopes made by J. W. Fecker.  Fecker was in business many years before
Unertl opened shop.  In fact John Unertl sharpened his skills as an employee of
Fecker prior to leaving around 1934 to start his own business.  Also known by
scope historians is the fact that the J. W. Fecker Company was the original
developer of the cage-type micrometer mounts later adopted by Unertl and
others.  If you can locate a copy of the May 2002 edition of The Accurate Rifle
magazine, it contains an excellent article titled, The Life and Times of J. W.
Fecker by Clarence Anderson.

In every aspect Fecker scopes are as well made as a Unertl, possibly better.  In
fact, in some respects a Fecker scope could be considered a notch above a
Unertl.  During the process of finding a suitable scope for my rifle, I ran across
two very nice Fecker scopes and bought both of them.  Later I purchased a
third.  Since Fecker’s are not as well known and readily available as Unertl’s, I
found that a Fecker in excellent condition can be purchased for significantly less
than a Unertl of comparable condition.  When comparing a Fecker to a Unertl it’s
evident that both are of very similar construction.  But Fecker’s have a unique
feature not found on Unertl’s or on other similar scopes.

Fecker scopes have an easy to adjust parallax/focus adjustment located in the
middle of the scope body.  The profile of a Fecker has been humorously
described as being similar to a chicken snake that has recently swallowed an
egg.  In actual use, when the scope is mounted on a rifle, the adjustment is easier
to reach and adjust than one located at the objective end of the scope.  It’s a
significant improvement over the crude screw and washer adjustment found on
the previously discussed Unertl Small Game Scope.  In addition, the
magnification of one of my ¾” tube Fecker’s was verified to be 10-power and
the other 8-power, both exceeding the 6X power of the Unertl Small Game
Scope.  Unertl and others may have produced ¾” tube body scopes that exceed
6-power magnification, but none that I’m aware of meet the NRA requirements
that any ocular or objective lenses, adjusting or assembly rings to be less than 1”
in diameter.  Refer to the next section discussing how to determine scope
magnification if the scope is not marked.

Below is a photo of my two ¾” tube Fecker scopes.  Both are the same length
(20.5”) although the one in the foreground appears longer due to being closer to
the camera.  The scope in the background (serial # 2385) is the older of the two.  
The one in the foreground is serial # 5588.  You can clearly see the mid-scope
parallax adjustment and slight differences in the design, although both work the
same way.  Also notice the left adjustable rear mounts are slightly different.  It’s
somewhat hard to discern in the photo but the top of the turrets on the top scope
mount are smooth and rounded which the turrets on the bottom scope mount have
flat tops with a small cavity machined in them.  Also looking close you can see
the Pope-style rib or rail that runs on top of each scope between the parallax
adjustment and the objective lens bell housing.  Also evident is the scope stops,
which are the thin circular rings clamped around the tube body and the rib.  Prior
to firing the rifle the scope is pulled (slid) back until the clamp contacts the front
mount.  When the rifle is fired, due to recoil, the scope slides forward in the
                            Measuring Scope Magnification (Power)

Although the magnification is not marked on the scopes, the newer one in the
foreground is 8X and the one in the background is 10X.  I verified the power of
both using two independent techniques.  By the way, the 19th and early 20th
century term used to indicate a scopes magnification or power was diameters.  
Therefore, a 6X scope was referred to as a 6 diameter scope.

One technique is based on the telescope "rule of thumb" formula that the exit
pupil diameter is equal to the diameter of the objective lens divided by the
power.  Put another way, the power is equal to the objective lens diameter
divided by the exit pupil diameter.  The objective lens diameter is very easy to
measure.  The diameter of the exit pupil is the size of the image projected on the
pupil of your eye when looking through the scope.  Measuring the exit pupil is a
little more complicated.  But with a little work and preparation it’s not too hard.  
To make a good measurement the scope must to be held steady, not rigidly
mounted, but held sufficiently steady to make a measurement of a focused spot
around 0.065” in diameter.

An easy way is to just lay the scope on a table.  Now align a bright light source,
lamp for example, approximately 2 to 3 feet in front of the scope.  It must be in
line with the scope and objective lens.  In other words, aim the scope directly at
the lamp as if you were sighting it on the lamp.  If aligned properly the image of
the light source should pass through the scope and form a small spot on a piece
of paper held within inches of the eyepiece (ocular lens).  With the scope on the
table and focused on a bright light, I taped a piece of paper on the back of a
chair and slid it to within inches of the scope.  If the light source is too far away
from the scope it may not supply sufficient light to illuminate the full spot or, if
too bright, may flair out on the paper making it difficult to define and measure
the spot edges.  Move the paper back and forth until the spot is focused to the
smallest diameter.  Grab your vernier calipers and measure the spot diameter.  
Divided the diameter of the objective lens by the spot diameter and you have
the approximate power of your scope.

Another, possibly easier method for some is to use the time honored technique
of looking at a small far away object with one unobstructed or "naked" eye
while looking at the same object through the scope with the other eye.  Then,
while superimposing both images over each other, estimate how many times the
image seen by the naked eye will fit into the larger image seen through the
scope.  Admittedly this can be a little tricky.  It requires a very steady rest and
the ability to concentrate on both images at the same time, which some find hard
or impossible to do.  In performing this highly scientific procedure an excellent
object to look at that offers a great reference image is a brick wall, better yet a
brick column.  If you are able to master the technique, just count how many of
the small bricks seen with the naked eye fit into one of the large bricks as seen
though the scope.  The answer is the approximate scope power.  If circles are
used rather than bricks, it's easy to understand where the old term diameters
originated to define the power; for example a 6 diameter scope.

Short Malcolm-Style Scope Mounting Adapter Rail for Browning
                              or Winchester M1885 BPCR

If you’re like me and prefer to avoid having additional mounting holes drilled
and tapped in your rifle barrel, there’s an alternative solution when mounting a
short externally adjustable Malcolm-style scope on a Browning or Winchester
M1885 BPCR.  Steve Earle, the well-known supplier of scope blocks for
externally adjustable scopes, is now offering a scope block rail that will attach
using the existing factory holes.  For more details on Steve’s scope rail see the
article titled

Mounting a Scope for Long Rang Creedmoor Matches

Montana Vintage Arms notes on their web site that their long range Creedmoor
Mount is not recommended for their 23” scope on a 30” or longer barrel.  
Further stating that at the top of travel the scope will be pointed at the barrel,
thus obstructing the view.  Until recently I had not given the comment much
thought since I had no plans to shoot past 500 meters.  But if you are planning
on using an externally adjustable scope out to Creedmoor ranges (800 yds to
1000 yds) you should be aware of potential problems when attempting to use a
short scope.  The following example will highlight the problem.

Let’s consider a 550 gr. bullet with a 0.350 ballistic coefficient being shot out of
a .45-90 caliber 34” barrel rifle at 1250 fps.  If the rifle is sighted to hit dead on
at 100 yds., a ballistic calculator will indicate an additional bullet drop of 165
MOA at 1000 yds.  Using the simple sight formula noted earlier, the rear mount
would have to be adjusted up a minimum of 0.33” to compensate for the bullet
drop.  Hence, a short scope around 23” or shorter will not work with normal
height scope blocks.  The combination of the short length and the scope tilt
necessary for 1000 yd shooting would result in the scope image being partially
or completely blocked by the muzzle end of the barrel.

To confirm the problem the 18" Leatherwood mounted on a caplock muzzle
loader and pictured earlier in this article was used.  The rifle has a 33” barrel
and the front (objective end) of the scope is 21.5” from the muzzle.  The scope
mounts are spaced at 7.2” and the scope was adjusted to hit dead on at 75 yds.  
After loosening the rear mount and sliding it off the block, a narrow wood
wedge was inserted under the mount base, between the mount base and top of
the block.  The wedge was slowly pushed forward, raising the rear mount.  The
blurred image of the muzzle appeared in the bottom of the sight image when the
mount was raised 0.22”.  At 0.31” the blurred image touched the cross hairs and
obscured the lower half of the sight image.  At approximately 0.41” the sight
image was completely obscured by the blurred image of the barrel.  Therefore,
if you plan on using a scope for Creedmoor competition you’ll have to go with a
longer scope in order to mount the front or objective lens end close to the
muzzle or use higher than normal scope blocks under the front and back mounts
of a short scope.


At this point in your reading you may have the feeling you’ve missed something
and are wondering what happened to my plans to mount a Leatherwood on my
BPCR using a “de-clicked” Unertl rear mount.  I believe it’s still an excellent
idea and likely the most cost effective solution available.  My plans were
changed due to coming across a couple of good deals on Fecker scopes
complete with silhouette legal mounts.  The amount I paid for each Fecker was
less than the cost of a Leatherwood and separate Unertl or D. Z. Arms mounts.  
In addition, the Fecker scopes feature a Pope-style sliding rib feature.  
Remembering the earlier comments made by Randy Oates, the owner of R.H.O.,
I’m not convinced a sliding scope is necessary.  But since the feature is
available on the Fecker’s, I’ll use it.

One area I did not discuss in any detail is the option to install mounts in the
existing dovetails on your rifle barrel.  Modern day mounts or scope blocks
made from good quality steel may very well offer a satisfactory solution for
dovetail mounting, but I’ve been warned to stay away from dovetail mounts in
general as they are prone to work loose.  If the dovetail blocks are sufficiently
hard the barrel steel may not be.  A long Malcolm style scope is much heavier
than the typical front sight on a BPC rifle and therefore puts significant lateral
stress on the dovetail slot.

I’ve covered and discussed several options for “scoping” a BPCR, including
USA made top-of-the-line modern day replicas, mixing and matching original
models with silhouette legal mounts or with modern copies of legal mounts, and
a couple of imported models.  If money is not an option, in my opinion, the best
solutions are a MVA scope with D.Z. Arms mounts or a complete D.Z. Arms
setup with scope and mounts.  Lower cost solutions include the standard MVA
scopes and mounts and the MVA B-Series scope and mounts.  The lowest cost
available solution that I would recommend is the Leatherwood with D.Z. Arms
mounts along with the D.Z. Arms sliding locking ring.  The only other items
required to install the scope and mounts are the correct scope blocks (bases)
and the option of an adapter rail discussed earlier from Steve Earle for the
modern Browning or Winchester BPCRs.

But, as the title of the article implies, this was an exercise to find a cost
effective solution.  To that end the most cost effective solution is to mount a
Leatherwood 18” 6X scope with a set of de-clicked Unertl mounts.  If a
Leatherwood scope is mounted with either D.Z. Arms or Unertl-style mounts
and a sliding feature is desired, a sliding lock ring will be required to ensure the
scope does not rotate as it slides under recoil and is returned to “battery”.  
Hopefully I've provided sufficient information to help you understand the
various other options available and come to a decision.

In Closing & References

In closing, I’d like to leave you with a couple of references:

A good guy you need to get to know is Steve Earle.  Steve supplies dovetail-
type scope blocks for many old and new mounts for external adjustable scopes.  
He can fit just about scope mount and rifle configuration and supplies the
adapter rail for Browning and Winchester BPCRs mentioned earlier.  Steve can
be reached at Steve Earle Products, Inc., 24 Palmer Rd., Plympton, MA 02367,
Phone: (781) 585-3929,
http://www.steveearleproducts.com/, Email: steven.m.

Finally, for a list of companies that can help you mount your scope or return
your damaged scope back to operating condition, see the article titled

Now you know everything I do about mounting a scope on a BPCR.  Have an
enjoyable time with your scope mounting and shooting and come back now and
then to check in to see what new information or items have been added to my
web site.

Wishing you great shooting,