arduous journey through the “Lilliputian World of Lands
and Grooves” started nearly three years ago. As the
journey began it was believed to be just a short
lackadaisical romp, but that belief was short lived.
For as we proceeded, vast new vistas of knowledge
appeared, taking one this way and that down the avenues
of discovery. In truth this article was written,
rewritten and rewritten again and again over a three
year period as new advances in the chemistry of bore
cleaning compounds appeared on the commercial market.
What made the pilgrimage possible was a Gradient Lens
Corporation Hawkeye® Bore Scope. For the first time,
the inside of a barrel became visible to the naked eye.
For the first time, the smears on a dry patch did not
have to be examined and evaluated — for now one could
actually see if the rifling was truly clean.
Our instrument of
discovery a Hawkeye® Bore Scope and our pot of
gold, Slip 2000tm, and Bore Tech miracle
odyssey begins in the late spring, 2003. After
check-firing a number of varmint rifles that were to be
taken on a week long jaunt to Montana after prairie
dogs, the tedious job of cleaning was begun. Glancing
up from the eye piece, and turning towards Moe Scharhon,
one of my shooting and hunting partners, I remarked in
an exasperated tone, “It’s still not clean!” Our
accepted routine of cleaning had been performed, but
smears of copper and layers of black carbon still
remained visible in the rifling.
My involvement in the cleaning of firearms is not due to
enamored interest in the process, but due to a desire to
make the rifles shoot as accurately as possible. For
me, shooting is fun — cleaning is work! So the best —
read that the fastest, and easiest way to clean a
firearm — is the true goal.
A Hawkeye® Bore Scope had been sent to me for
evaluation by Ken Harrington, Gradient Lens’ Reseller
Manager. I was so impressed by that first encounter
with the Bore Scope at the range the following day a
call was placed and credit card numbers were given. I
simply had to own one. To say that the Hawkeye® has
excited my imagination and lent a desire to let others
know what a superb addition it is to any shooter’s
collection of cleaning implements is a major
Returning from the Montana hunt, the rifles were set
aside, as an extraordinarily fine summer concluded in
the Pacific Northwest, and family involvements
intervened. The “dog” rifles sat beckoning, so with the
coming of the fall rains, and the recruiting of Moe and
my other hunting partner, John Barnett, a plan was
developed to determine the effectiveness of every bore
cleaning solvent we could lay our hands on, and to
reevaluate the techniques used in the cleaning process.
The battery of rifles waiting to be cleaned consisted of
five .223s, four .22-250s, two .220 Swifts, and a 6mm
Remington, most having been shot between 200 and 300
times. There were exceptions of course, as two of
John’s rifles topped the “dirtiness scale” with over
1200 fired rounds fired, each. Also to be cleaned was a
semi-automatic belt fed .308 Browning 1919A4 that had
had over a 1000 rounds down its tube at a rate which
made the barrel shroud way too hot to touch.
The regimen decided upon was to first wet the bore with
two patches soaked with one of the many name brand
petroleum based bore cleaning solvents on hand. That
was followed by a 50 to 75 strokes with a bronze brush,
after which the solvent was allowed to stand for 5
minutes. Finally the bore was dry patched. Then each
bore would be checked visually with the Hawkeye®.
If copper was found to be present, a couple of patches
soaked in copper solvent would be pushed through the
bore and the rifle set aside for five minutes to allow
the solvent time to work. If instead the inspection
showed a evidence of carbon fouling, the bore cleaner
was reapplied. The process would be repeated as many
times as necessary, depending on which type of fouling
was found lingering in the bore. In some cases, as many
as ten repetitions were necessary. When it appeared
that all of the fouling that could be removed chemically
was removed, J B’s Bore Cleaning Compound was applied to
a used bronze brush and was scrubbed back and forth in
the bore 50 to 75 times. At which time bare metal would
As can be seen, to get a firearm’s rifling truly clean
is real drudgery!
After the cleaning gala was concluded, curiosity
continued to nag at me to persevere in the search for
new chemicals that would make cleaning a rifle a lot
less work. In the months following the three day
cleaning jamboree a plan was conceived. In January the
SHOT SHOW (Shooting, Hunting, and Outdoors Trade Show)
would be attended with the mission to solicit every new
cleaning solvent found for testing.
But first let’s discuss the unit that provided the venue
to enable the discoveries of our miniature land to
The Hawkeye® Precision Borescope
Hawkeye® model that was purchased was the 17 inch deluxe
version, complete with angle eyepiece and carrying case.
Although one can get along without the angle eye piece,
its use eliminates the necessity of bending over or
squatting down to align the eye with the borescope and
hence the bore’s axis. To be able to stand upright and
see the rifling of a firearm one is cleaning is well
worth the angled eye piece’s added expense. The angled
eye piece is easily attached to the Borescope body by
merely pulling back on the finger grooved ring and
snapping it into place.
The Hawkeye® consists of three components: the body
which has an eye cup that adjusts so that the image can
be brought into focus and to which is attached a slender
metal tube. The metal “optical” tube serves two
functions; it transmits the image to the eye piece and,
at the same time, transmits light forward to illuminate
the interior of the bore.
The second component is a hollow metal “mirror” tube
which contains a very small mirror on one end and a
knurled knob on the other. The “mirror” tube is simply
slipped over the “optical” tube on the body and by
rotating the knurled knob on the mirror tube, the
reflection in the mirror permits examination of the top,
bottom and sides of the rifling at any point in the
barrel. The knurled knob is notched relative to the
position of the mirror so the comparative position of
the rifling can be determined.
Protruding at right angles from the body is the
attachment point for a light source. The standard light
source is a modified Mini-Maglite®.
As stated by Ken Harrington, a word of caution is in
order, these two tubes can be bent if not supported when
inserting them into the bore and the little mirror can
be broken if dropped or slammed against something hard.
This is not to imply the unit is not sturdy, for it is,
but care must be taken with this expensive, quality
Both the eye cup on the body and the angled eye piece
can be adjusted to focus the unit. In practice the main
focus on the Hawkeye® body was adjusted first, and then
the adjustment tube of the angled eye piece was turned
to produce a crystal clear image.
With the light source attached to the Hawkeye®, new
panoramas are opened to the shooter — magnified 25
times. The sharpness of the edges of the lands were
apparent, as were minute pits filled with carbon fouling
found in one newer barrel. When looking forward from
the lead to the muzzle on a well shot rifle, one might
see the rounded edge of the lands slowly become square
and sharp. Some barrels displayed tiny cuts and
abrasions, both horizontal and vertical to the lands; a
result of the rifling process. With little effort one
can differentiate between an expensive barrel and one of
lesser cost as the former’s bore is smoother with razor
sharp edged lands. Fire crazing of a bore caused by hot
powder gases that occurs after repeated firing and which
acts as a collecting point for copper fouling was
clearly evident in one rifle. (See Figure 1). In other
rifles, fire crazing was observed starting at the lead
and included the first couple of inches of the rifling
making one surmise that this effect starts at the
chamber end of the barrel and works forward. The
condition of the chamber, as well as the throat, can be
observed, and for the first time the very edge of the
crown can be checked — from inside the barrel.
Two types of fouling
understand the panorama that unfolds through the
Hawkeye’s® eyepiece a shooter must first understand what
fouling is. Basically there are two types of fouling;
carbon fouling which is the result of the propellant
gases created by the burning of the powder, and the
smearing of copper based jacket material deposited on
the rifling as the bullet proceeds down the bore.
Layers, they really do exist!
borescope clearly proved the fouling occurs in layers.
During the cleaning process one could observe a bright
layer of copper which, when removed, revealed a black
layer of carbon. When the carbon layer was eliminated,
yet another layer of copper became visible.
It can be hypothesized that the abundance of “one step”
cleaning products are a result of the purchasing choices
of the shooting community who want a simple, effortless,
no fuss cleaning procedure. Unfortunately, most of the
combination carbon/copper cleaning solvents tested did
not work as well as products designed to remove a
specific type of fouling. If the product removed carbon
it was usually not very effective on the copper, and
It also saddens me to report that regardless of the
current avalanche of advertising “hoopla” and the
endorsement by some “big name shooters,” most gun
cleaning solvents that claim to remove carbon do not
work at all, or are only marginally effective.
The problem of course is how can an individual determine
which of the myriad of commercial products available in
the market place are effective? Without a Hawkeye® Bore
Scope one can’t!
What do you see through a Hawkeye®?
first look at a fouled bore through a Hawkeye® yields a
murky image, as if the rifling were being viewed through
a veil of thin smoke or the bore had been smeared with a
gray colored charcoal drawing pencil. An example of a
smoky visage is seen in Figure 2. Also visible in
Figure 2 are light strips of copper fouling found in the
corners of the grooves, and a thin coating of copper on
the tops of the lands. This bore is only lightly
fouled, having had only 20 or so rounds fired through
After the first cleaning cycle the smoky overlay is gone
and, although the bore is still dirty, it has a sheen to
it that can be seen in Figure 3. Additionally, Figure 3
is an excellent example of where powder fouling is
interspersed with, and in some instances under the
copper fouling. Note the dark, almost black, color of
the multiple layers of carbon contamination, which
suggests that if further shots were fired the color of
the carbon build-up would darken. Also take notice of
the heavy deposits of copper bullet jacket material on
the right side of the photograph.
To really understand how much can be seen through a
Hawkeye® borescope, examine Figure 4 closely. Pictured
are examples of exceptionally dirty barrels from the
2004 Montana varmint expedition. The first three images
display examples of heavy carbon fouling obscuring
underlying copper layers. The fourth image is the
interior of a Browning 1919A4 semi-auto barrel laden
with copper after over a thousand rapid-fire rounds had
been shot. Bore Tech’s new copper solvent, Eliminator
was applied to the 1919A4 barrel, and all the copper
seen was removed with just two applications (see section
A heavily fouled bore is exhibited in Figure 5. This
close-up shows both copper and carbon fouling spread
evenly over the lands and grooves. Notice that the
fouling is not built up in a specific area as in Figure
2, but is the precursor to the total black bores shown
in Figure 4 which undoubtedly would occur if additional
shots were fired.
And finally eureka, a completely clean bore that shines
brightly from the top of the lands down to the bottom of
the grooves (Figure 6). This barrel is squeaky clean!
The dark area at the top of the image is caused by light
Carbon fouling is extremely difficult to remove since it
is insoluble and must be eliminated by either abrasion
or by the use of surfactants and detergents. The way
surfactants work is to reduce surface tension and
through a chemical electrical charge which breaks the
bond between the carbon and the bore’s steel, thus
allowing the carbon fouling to be lifted free.
A prime example of how surfactants work is dishwashing
detergents. A dish is immersed in soapy water and the
detergent reduces the surface tension between the
crusted food and the plate and with a swish of a sponge
or dish cloth the plate comes clean.
The efficacy of a bore solvent which claims to remove
carbon is a function of the efficiency of its surfactant
components. (Bore solvent is an oxymoron, since carbon
does not dissolve.) Most petroleum based cleaners use
thin oils such as kerosene or penetrating oils hoping
the oil will get between the carbon and the steel bore.
The results of our tests proved that most brands of
petroleum based cleaners do little or nothing to aid in
removal of carbon fouling.
As in “doing the dishes” a little mechanical agitation
(brushing with a bronze brush) is required to effect the
carbon separation from the steel and to add oxygen to
help activate the cleaner. A number of the combination
carbon cleaner/copper solvent manufacturers are now
recommending nylon brushes as a substitute for bronze
brushes for this function. The reason for this change
of position is that they have received numerous
complaints from customers that the copper remover part
of the solvent rapidly eats up bronze brushes requiring
frequent brush replacement. In my experience nylon
bristles are not stiff enough to provide the appropriate
level of agitation needed for carbon removal.
Before the borescope allowed close observation of the
interior of the barrel, it was my belief that brushing a
bore was similar to using a wire brush on a rusted piece
of metal — the carbon fouling in the bore would be
stripped out by a bronze brush as if it were the rust.
Not so! Scrubbing serves two purposes, in that it
loosens the amount of carbon fouling released by the
surfactants while at the same time allowing the solvent
greater access to further fouled surface area.
Perhaps the greatest error most shooters make is
patching out the bore after brushing without allowing
any time for the solvent to do its job. To emphasize
this very important discovery let me restate it — a one
must allow sufficient time to for the chemicals in any
bore cleaner to work. Applying a solvent, brushing and
then quickly patching it out is a waste of solvent,
patches and elbow grease!
Marvels of modern science
trip to the 2004 SHOT SHOW had yielded samples of two
new bore cleaners; Hoppe’s Elite Gun Cleaner and Bore
Tech’s Carbon X. A major technological break-through
had taken place, yet surprisingly little had been
published about them. It was the discovery of
surfactants that would remove carbon, and when combined
with detergents into water based compound, have in my
opinion, created a whole new generation of bore
For the first time there were carbon removers available
that would actually dislocate the layers of carbon
fouling! Both of the “Elite” and “Carbon X” were far,
far more effective carbon removers than any of the
petroleum based products previously tested. Another
important feature is that these two products are
odorless, non-toxic, and biodegradable.
Returning from the prairies of Montana and South Dakota
both “Elite” and “Carbon X” were used to clean our well
shot rifles. As before, two patches soaked in the new
bore cleaners were pushed through the bore, and then
each bore was scrubbed with a bronze brush for 25
strokes. The rifles were then set aside to allow the
bore cleaner chemicals to work for about 20 minutes. It
was ascertained by testing that there was no advantage
to extending the barrel “soaking” time beyond a 20
Although “Elite” and “Carbon X” were a major leap
forward in reducing the effort required to remove carbon
fouling, they still required five to seven cleaning
cycles to get a bore clean. Still no magic bullet!
the coming of winter in the Northwest there was time for
reloading next year’s supply of ammunition and catching
up on my reading of the stacks of magazines which always
seem to accumulate. So one rainy, blustery day after
the New Year (2005) an ad was spotted in a magazine for
a product named Slip 2000tm’s Carbon Cutter that claimed
it would remove carbon easily. The following day a
phone call was placed to purchase some of this “magic
elixir.” As luck would have it the call was made
around noon, so instead of speaking to a receptionist,
the owner of the company Gregg Conner took my call.
I told Gregg that I wished to purchase some of his
company’s products and explained that their attributes
could be part of an article I was writing — if they
lived up to their advertising. Gregg graciously offered
to send a sample as he wanted to have his company’s
products included in our ongoing investigation.
Let me state unequivocally that Slip 2000tm’s Carbon
Cutter is the product which stands at the pinnacle in
its ability to remove carbon fouling from gun barrels.
At last there was a product that actually performed as
claimed — it really and truly removes carbon!
In just one or two regimens it removed carbon deposits
from moderately fouled bores down to bare metal. Used
in conjunction with Bore Tech’s Eliminator Copper
Cleaner on heavily fouled rifles, the sight of shinny
lands appeared within two to four regimens.
To show just how efficient Slip 2000tm’s Carbon Cutter
is, the AR-15 bolt from John Barnett’s rifle which had
over 3200 rounds fired through it was immersed in a jar
of Slip 2000tm’s Carbon Cutter for 20 minutes. Before
the immersion of the bolt in the Carbon Cutter several
of the most common and popular cleaning solvents in turn
were applied. In each case none or very little of the
carbon adhering to the bolt was removed.
Barnett’s AR-15 bolt was crusted and coated and appeared
as if it had been dropped in wet thick mud and allowed
to dry. But in this case the mud was carbon. Upon
removing the bolt from the jar of Carbon Cutter, the
caked on carbon flaked off when rubbed with nothing more
than a paper towel.
Another test of the efficacy of Slip 2000tm’s products
was the immersion of the gas piston from a Beretta 390
shotgun and a Browning Invector Plus choke tube. Again,
the petroleum based cleaners were tried on the piston,
to no avail. After waiting 20 minutes the piston was
removed from the jar of Carbon Cutter and the fouling
was simply removed with a paper towel. As shown in
Figure 7, the piston was shiny right down to its plated
But yet another surprise awaited! The application of a
bronze bore brush to the inside of the Browning choke
tube easily removed the accumulated plastic wad material
In one heavily fouled varmint rifle it was observed that
deep within the rifling at the junction where the lands
and grooves met there lurked a final thin layer of burnt
on carbon. Although the rest of the bore was bright
metal that final layer of carbon stubbornly refused to
be removed chemically. An application of J B’s Bore
Cleaning Compound (available from Brownells) on a well
used bronze brush was applied to finally eliminate the
To answer the obvious question — a test was arranged to
find out how the abrasive qualities of J B’s stack up
against Slip 2000tm’s Carbon Cutter? Even after five
applications J B’s failed to get a rifle’s bore down to
bare metal. In my opinion Carbon Cutter had won the
contest “hands down,” but J B’s was invaluable in the
removal of that last stubborn carbon clinging to the
corners of the grooves where chemical removal proved to
be inadequate. It would seem logical to apply chemical
removers first and only use an abrasive such as J B’s to
remove what the chemicals could not.
In a subsequent phone conversation with Gregg Conner,
the question was raised that in his company’s literature
it was noted that two products, Carbon Cutter and Gas
Piston Parts and Choke Tube Cleaner looked identical and
were priced the exactly the same. Gregg told me that I
had guessed correctly and that the two products were the
same but were being marketed under different labels. It
seems that Gregg, besides owning an industrial chemical
company is a shotgunner and the original product was
developed to clean his shotguns and chokes. Gregg
further explained that the reason for the two labels was
that the U.S. military and many law enforcement
agencies, who are now customers, would be a little
skeptical of a product labeled for cleaning shotgun gas
pistons and choke tubes would work well on cannons,
assault rifles and machine guns.
A fact to be cognizant of is that all of the new
generation of carbon fouling removers are water based
and are so proficient that they completely strip all
imbedded oils from any metal they come in contact with.
Therefore, when the carbon/copper removal phases are
completed it is extremely important to apply a
protective lubricant to the firearm to prevent the
possibility of rusting. Notice should be taken that the
word lubricant was used instead of oil. Here too there
has been a major breakthrough in chemical technology
that is superior to most of the petroleum-based products
used by shooters.
Slip 2000tm’s Gun Lube is a synthetic, biodegradable,
non-toxic lubricant. Unlike petroleum based oils which
have a flash point of about 200 degrees, Gun Lube’s
flash point is over 2000 degrees. What does that mean?
It means that when used as the lubricant on the bolt of
an AR-15, the lubricant does not burn off when the rifle
Additionally, Gun Lube does not combine with carbon to
gum up and form sludge or crusting, it also does not
collect common dirt, turning it into grime. Perhaps the
most important gain from Gun Lube is that it enters the
pores of the steel and makes future cleaning even faster
and easier. This was verified by one of our tests. An
AR-15 whose bore had received a coat of Gun Lube cleaned
to bare metal using Slip 2000tm’s Carbon Cutter in only
one regimen, this after having 80 rounds fired through
Copper fouling is far more easily removed than carbon
fouling, as it can be dissolved in a solvent. An
analogy of that would be the dissolving of a teaspoon of
sugar in a cup of hot coffee. Presently, most of common
copper removers contain ammonia in strengths between 2
and 7%. Ammonia is effective, but it is also a toxic
chemical, has an unpleasant odor, and can cause skin
Again, a new generation of solvents has been recently
introduced that are vastly more efficient, are
biodegradable, non-toxic and odorless; something many
spouses will undoubtedly appreciate.
My first choice for a copper remover is a product from
Bore Tech named “Eliminator” which puts ammonia based
products in about the same class as buggy whips.
After passing an Eliminator soaked patch down a fouled
bore for the first time, the patch showed a suspicious,
tell-tale light blue-green color indicating the presence
of copper fouling. In my experience, a blue-green color
rarely appears by simply passing the first “wetting”
patch of a copper solvent through a bore. Normally, a
period of time has to elapse to allow the copper to
dissolve before a subsequent patches display the
My immediate reaction was that the color on the patch
was a reaction between the Eliminator and the brass
jag. The brass jag was replaced with a steel one to
eliminate that variable, (something repugnant to the
maintenance of fine rifle barrels); still the evidence
of continued copper removal appeared. Eliminator
solvent started doing its magic at once!
The correct way to use Eliminator is to push two
successive wet patches down the bore, then allow the
chemicals in the solvent an interlude of time for them
to do their work. It was found that about 15 to 20
minutes on a heavy concentrate of copper was normally
adequate. It was also discovered that brushing was not
required as all of the agitation necessary for
activation could be supplied by merely pushing the
application patch back and forth down the bore
“Eliminator,” which contains no-ammonia, hence has no
odor, is biodegradable, does not affect the skin, and is
in my opinion the most efficient copper bore cleaner yet
the collector, varmint hunter, or accuracy shooter, a
Gradient Len’s Hawkeye® borescope is an indispensable
tool. Its introduction allows visual inspection of a
bore to see if it is clean and to monitor its
condition. After all the years of cleaning firearms, of
scrubbing, of swabbing and brushing, now for the first
time the condition of a bore can actually be clearly
viewed. The Hawkeye® is not inexpensive, depending on
model and accessories, the price ranges from six hundred
to seven hundred and fifty dollars, about the price of a
fine rifle. A borescope’s value lies in that it is not
only a cleaning accessory, but it also allows one to
check the bore of a used firearm before purchase.
Without the Hawkeye® the discovery of the effectiveness
of these new carbon and copper removers would never have
been possible. These new cleaning products really do
The question might be raised, “What were the other
products that were tested?” The names of the myriad
other products used in this study have been purposely
been omitted since Bore Tech’s Eliminator, and Slip
2000tm’s Carbon Cutter and Gun Lube were clearly far
superior to all other products tested.
the course of this trip through the Lilliputian World of
Lands and Grooves, the Rangemaster at my home range,
after having seen the borescope in action, asked me to
return with the Hawkeye® to inspect a barrel he had at
home, which he believed to be rough. During my return
visit a few days later, as the barrel was being examined
in the clubhouse, an experienced, elderly shooter
observed our machinations with mild indifference.
The gentleman then began to expound on his personal
cleaning methods and stratagems. He related that he
cleaned his rifles immediately after firing and then
re-cleaned them the next day and again a week or so
later. He said that his method of cleaning had been
used for a number of years, and that he knew all of his
rifles were clean! He then said that he didn’t see the
need to spend a lot of money on an expensive gadget.
And with that last remark walked out of the door with
the wave of a hand in farewell.
A few seconds latter we looked up as the door was opened
and this same individual returned, this time carrying a
pre-64 Model 70. “Would you check the bore on this for
me?” he asked.
“Sure, glad to,” I replied.
Inserting the bore scope, I asked, “Has this one been
“Yes, it was not shot today so it is clean,” was his
“Well you better come take a look then,” was my answer,
as the bore was pitch black and the lands were covered
with a heavy layer of copper.
The gentleman raising his eyes from the eyepiece and
with frown covering his face said, “Where can I buy one
As was related early on in this article, after trying
the Hawkeye® just once at the range, I had to own one
Gradient Lens Corporation
207 Tremont Street
Rochester, NY 14608
Bore Tech Products
100 Emlen Way, Suite 108
Telford, PA 18969
Oakland, CA 94607
South Front Street
1) Fire crazed markings covered with copper
appeared in this well shot Remington BDL.
(Figure 2) This
lightly fouled bore looks like it is being
viewed through veil of smoke.
3) Strips heavy carbon fouling are evident on
the left and a band copper fouling is seen on
Notice black color of first three pictures and
the underlining copper tint. The lands and
groves in picture four depict excessive copper
fouling after 1000 rounds.
5) A heavily fouled black colored bore with
scratches on the lands
6) Eureka, a squeaky clean bore.
8) Copper fouling hiding deep down within the
lands of a partially cleaned bore. Something
that could never have been spotted without the
aid of a Hawkeye® bore scope.
(Figure 7) From
carbon coated to clean in one easy step with
Slip 2000tm’s Carbon Cutter.