Note: Descriptions are shown in the official language in which they were submitted.
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Method and cleaning agent composition for
cleaning the barrel of a gun.
The present invention relates to a method for
cleaning the barrel of a firearm.
The barrel of a firearm has to be cleaned at
regular intervals to remove the remnants of bullets and
combustion residue such as soot, powder and burnt
grease, accumulated in the barrel. In this context,
bullet remnants means the metal residue left in the
barrel from bullets, such as, in the case of commonly
used bullets containing copper, residue of copper,
possible copper compounds and other alloyed metals,
e.g. copper and zinc residue and, in the case of lead
bullets, lead residue.
Various methods and cleaning agents for the
cleaning of a gun barrel are known. However, current
cleaning methods often involve mechanical cleaning by
scrubbing the barrel with a hard brush, such as a bronze
brush. For example, in a commonly used cleaning
method the cleaning agent contains aluminium
particles which scrub off impurities from the barrel
surface during mechanical cleaning.
Mechanical scrubbing is a laborious and time-
consuming operation. Naturally it also causes wear of
the barrel surface, thus shortening the service life
of the firearm.
To remove the copper residue left in the bar-
rel from copper bullets, cleaning agents acting chemi-
cally on copper have also been tried. This type of
cleaning agents usually contain ammonia, and the prob-
lem has been that ammonia is very volatile, i.e. the
cleaning agent quickly becomes ineffective as the ac-
tive component evaporates. Furthermore, when such
cleaning agents are used, the barrel must nevertheless
be cleaned mechanically as well, so they do not elimi-
nate the drawbacks associated with mechanical clea-
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ning. Moreover, the evaporating gases are detrimental
and undesirable. The specification of European Patent
Application No. EP 0 075 113 Al entitled Cleaning Agent
for Barrels, published on March 30, 1983 presents a
composition of substances that contains ammonia or amine
compounds mixed in a gel to prevent evaporation.
In addition, the commonest cleaning agents
currently used are relatively expensive.
The object of the present invention is to
eliminate the drawbacks referred to above.
A special object of the invention is to pro-
duce an effective cleaning method of a new type that
reduces the need for mechanical cleaning and thus sig-
nificantly extends the service life of the barrel.
A further object of the invention is to pro-
duce a new type of cleaning method that is faster and
more user- friendly than earlier methods.
The invention is based on the unexpected ob-
servation made during investigations that bullet resi-
due can be removed by using a foam that, in the case
of bullets containing copper, contains an alkaloamine
and, in the case of bullets containing lead, a nitrate
salt. Thanks to the invention, a method has now been
discovered that makes it possible to effectively and
quickly remove the metal residue left by bullets in a
barrel, without damaging the steel of the barrel.
In the method of the invention, ammonia can
also be used for the cleaning of a barrel because the
foam prevents evaporation of ammonia, so the cleaning
agent does not lose any of its effectiveness.
For the first time, the present invention
produces a firearm cleaning method that uses a foam
containing substances that remove bullet residue. The
foam to be used can be produced by using a tenside. The
tenside may be any commonly used, foam-producing
surface-active substance, such as coconut diethanola-
mide.
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Further, nitrate salt has now been used for
the first time as a material that chemically removes
bullet residue. It was observed during investigations
carried out that lead residue in a barrel reacts due
to nitrate salt in a way that allows the lead to be
removed from the barrel surface without mechanical
scrubbing. The nitric salt used is preferably an inor-
ganic nitrate, such as alkaline nitrate, alkaline
earth nitrate or ammonium nitrate, especially sodium
nitrate. In the method of the invention, the cleaning
can be performed by using any substance that forms a
foam, preferably a consistent foam, that contains e.g.
exclusively nitrate salt, in which case it is appli-
cable for the cleaning of firearms using lead bullets.
The pH of the nitrate salt solution is preferably ad-
justed to an alkalic value if necessary. However, e.g.
in the case of sodium nitrate, no pH adjustment is
needed. There is no indication that, when used in the
manner described, nitrates cause wear of the steel ma-
terial of the barrel. The reaction product is removed
automatically from the barrel surface, or it can be
removed bv using only a soft felt plug, i.e. without
actual mechanical scrubbing. Thus, when the method of
the invention is used, bullet residue can be effecti-
vely removed from the barrel by wiping it with a mate-
rial or plug commonly used for the cleaning of fire-
arms, without damaging the steei material of the bar-
rel.
In an embodiment of the method of the inven-
tion, preferably a consistent foam containing an al-
kanolamine and/or a nitrate salt is used, in which ca-
se the method is applicable for the cleaning of both
firearms using lead bullets and firearms using cop-
per/copper compound bullets. In addition to its prima-
ry purpose in the method of the invention, the alkano-
lamine can also be used for the adjustment of the pH
of the solution to an alkal.ic value in connection with
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solutions containing a nitrate salt. The alkanolamine
is preferably monoethanolamine or diethanolamine or a
compound of these, especially monoethanolamine.
In the cleaning method of the invention, a
foam is used that contains about 1 - 80 w-%, prefera-
bly about 20 - 70 w-% nitrate salt, such as sodium
nitrate, and/or about 1 - 70 w-%, preferably about 1-
30 w-%, e.g. 2 - 25 w-% alkanolamine, such as monoet-
hanolamine or diethanolamine.
In the method of the invention, a foam is us-
ed that preferably additionally contains an organic
solvent for the removal of combustion residue such as
soot, gunpowder remnants and/or burnt grease. For this
purpose, any solvent or solvents, especially a water-
soluble/mixable solvent, may be used. In an especially
advantageous case, the composition contains under 50
w-%, e.g. 1 15 w-% methylpyrrolidone and/or under 50
w-%, e.g. 1 15 w-% butoxyethanol, which have proved
to be effective in removing combustion residue.
The amount of tenside used in the cleaning
method is e.g. under 50 w-%, e.g. about 0.1 - 25 w-%
of the composition, depending on the intended applica-
tion.
The foam used in the cleaning method may
further contain about 1 - 90 w-% added water. By va-
rying the amount of water, it.is possible e.g. to ad-
just the concentrations of the active substances as
desired. The amount of water added may be e.g. 5 - 60
In a preferable embodiment, an amount of un-
der 15 w-%, e.g. about 0.1 - 3 w-%, of sodium salt of
m-nitrobenzenesulfonic acid has been added to a compo-
sition containing alkanolamine to assist in removing
from the barrel surface the reaction products formed
by residue from bullets containing copper.
The composition used in t~-_==method of the in-
vention may additionally contain an amount of about
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0.1 - 30 w-%, e.g. 1 - 10 w-%, of a barrel protecting
substance, such as commonly known arms oil or prefera-
bly so-called cutting lubricant, which may be of semi-
synthetic or synthetic type and which prevents copper
5 from sticking to the barrel. The agent used for barrel
treatment may be a water-mixable substance or it can
be emulsified in water using e.g. a tenside and/or
solvent, such as butoxyethanol.
The composition of substances used in the
method of tht invention can be implemented in any sui-
table form. Preferably the composition is in the form
of a foaming liquid or, suitably, in the form of a
spray sprayable as a foam, in which case it is packed
in a container equipped to produce a spray, together
with propellants if required. The composition may also
contain an agent that increases viscosity.
In the following, the invention is described
in greater detail by the aid of examples, which are
only intended to illustrate the invention without li-
miting it.
Example 1: Producing a composition of substances for
use in the cleaning method of the invention.
A cleaning solution composed according to one
of the following alternatives is prepared:
w-% prefer- composition
Components red A B C D E
coconut diethanol-
amide 0.1-50 4 25 2 3
monoethanolamine 0-70 1-30 25 2 15 70
. sodium nitrate 0-70 20-70 40 20 70 40
methylpyrrolidone 0-30 1-15 5 15 5 10 5
1-butoxyethanol 0-30 1-15 5 15 5 10 5
sodium salt of
m-nitrobenzene-
sulfonic acid 0-30 0.1-3 1 3 2 10
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semi-synthetic
cutting lubricant 0-30 1-10 10 10 10 10
water added 0-60 1-30 10 10 12 10
When compounding the components, the sodium
nitrate is solved in the water added. It can also be
added to other components in the form of a rich water
solution. Instead of monoethanolamine, other alkanola-
mines can also be used, such as diethanolamine. When
the composition is produced in the form of a foaming
liquid, the formulation is performed by using a tensi-
de in an amount of e.g. about 0.1 - 30 w-%. When the
composition is produced in the form of a spray, the
amount of tenside used is e.g. 0.1 - 4 w-%. The con-
centrations of active components are selected e.g. on
the basis of the length of time the cleaning agent is
to be allowed to act in the barrel. This action time
may vary e.g. between 0.1 - 30 min., whereupon the
composition is removed by using a plug of a medium,
e.g. a felt plug.
The finished composition has an alkalic pH
value. The cleaning method of the invention is less
hazardous to the user and the environment than earlier
methods and the composition emits no toxic gases as
compared with previous compositions. Moreover, consis-
ting of cheap components, it is advantageous in res-
pect of cost. The composition used does not suffer any
loss of efficiency dur--ng storage or use. Furthermore,
the composition' used in the method protects the bar-
rel, and the addition of cutting oil has the effect
that a smaller amount of bullet residue, such as cop-
per, sticks to the barrel surface.
Generally, the cleaning method of the inven-
tion is applicable for the cleaning of the barrel part
of a firearm of any type and any size.
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Example 2=
An experiment was carried out to test the ef-
fectiveness and applicability of a cleaning method as
provided the invention, designed for firearms using
copper/copper compound bullets.
Composition of the foam used in the method
Components w-%
monoethanolamine ca.25
methylpyrrolidone ca. 5
1-butoxyethanol ca. 5
sodium salt of m-nitro-
benzenesulfonic acid ca. 1
coconut diethanolamide ca. 4
water added ca. 50
cami -cirntha+- i r
..~....~ ~.~.......~~..
cutting lubricant ca. 10
The composition was prepared in the form of a
spray. To clean a firearm, the foaming alkalic compo-
sition was sprayed into the barrel and allowed to act
for ca. 10 min., whereupon it was removed by pushing a
felt plug through the barrel.
The firearm cleaning method was tested in
field conditions during half a year. It was establis-
hed that the cleaning method worked in-cold and hot
weather. Moreover, the method was found to be effecti-
ve and easy to use.
In comparing a barrel cleaned by the method
of the invention was compared with a barrel cleaned by
the traditional mechanical method, the barrels were
inspected using an endoscope and it was established
that the barrel treated by the method of the invention
was in a considerably better condition, i.e. it showed
less wear and burn damage, than the reference barrel.
It is estimated that, by using the cleaning method of
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the invention, the service life of a firearm is exten-
ded by about 50 %.
