GB1605237A

GB1605237A - Tracer composition for small calibre ammunition

Info

Publication number: GB1605237A
Application number: GB1221475A
Authority: GB
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1974-04-02
Filing date: 1975-03-24
Publication date: 1985-06-19
Also published as: DE2415847C1; FR2555727A1; IT1068203B; BE827475A

Abstract

Coloured tracer composition for small-calibre ammunition whose projectiles comprise a coaxial bore of at least 4 mm in diameter, which composition is based on light metals and oxygenated compounds of the alkali or alkaline-earth metals and/or of copper, and containing, additionally, zirconium metal and salts of halogenated aromatic carboxylic acids.

Description

(54) TRACER COMPOSITION FOR SMALL CALIBRE AMMUNITION (71) We, DYNAMITNOBEL.

AKTIEMGESE1 LSCHAFT, a German Company, of 521 Troisdorf, Near Cologne, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly desribed in and by the following statement: This invention relates to a tracer composition for use, in particular, but not exclusively, in small calibre ammunition comprising an axial bore not more than 4 mm in diameter.

Conventional tracer compositions consist of a mixture of a lightweight metal, usually magnesium, an oxygen-containg salt of an alkali metal or an alkaline earth metal and a chlorine-containing organic binder. These chlorine-containing binders also serve as chlorine donors for the alkali metal or alkalineearth metal salt to be burnt, enabling the cation of the salt to be obtained, after burning of the composition, in the form of its chloride.

Examples of binders used for this purpose are hexachlorobenzene, polyvinyl chloride, hexachlorocyclopentadiene, hexachloroethane and chlorinated polyisopropylene with a chlorine content of approximately 67%.

When these tracer compositions are used in small-calibre tracer ammunition shells having an axial bore not more than 4 mm in diameter, traces which are not uniformly visible tend to be obtained when the cartridges are fired. In addition to non-uniform burn-up with a cartridge of this kind, the composition often does not even ignite.

According to the present invention, there is provided a tracer composition for producing a coloured trace, which comprises, in admixture and in particulate form, a lightweight metal, one or more oxygen-containing compounds of one or more alkali metals and/or alkaline earth metals and/or copper, metallic zirconium and salt of a halogenated aromatic carboxylic or sulphonic acid.

When a tracer composition of this kind is used in a shell having an axial bore not more than 4 mm in diameter, the problems referred to above do not occur. The composition burns up uniformly and the trace produced remains visible over the entire trajectory of the shell.

The zirconium content of a tracer composition according to the invention preferably amounts to from 5 to 25% by weight of the tracer composition. A zirconium content of from 8 to 13% by weight is particularly preferred. The zirconium used preferably has a grain size of from 0.001 to 0.04 mm, a grain size of from 0.()02 to 0.01 mm being particularly preferred.

The halogenated aromatic acid will usually be a mononuclear aromatic dicarboxylic acid chlorinated on the nucleus, that is a chlorinated phthalic acid, isophthalic acid or terephthalic acid. However, salts of monocarboxylic acids, for example nucleus-chlorinated salts benzoic acid and even sulphonic acid salts, for example nucleus-chlorinated salts of benzene sulphonic acid, can also be used. An alkali metal or an alkaline earth metal in particular, preferably calcium, will usually constitute the cation of the salt of the aromatic acid.

The salts of the halogenated aromatic carboxylic or sulphonic acids are preferably present in a tracer composition embodying this invention in a quantity of from 15 to 40% by weight. Quantities of from 20 to 30% weight are particularly preferred.

The other components of compositions embodying this invention are constituents of hitherto described tracer compositions.

However, the above-mentioned chlorinecontaining organic binders, such as hexachlorobenzene, can be omitted from tracer compositions according to the invention as they are not required.

Magnesium is preferably used as the lightweight metal. The choice of the cation of the oxygen-containing alkali metal or alkalineearth metal compound is governed by the required colour of the tracer composition.

Preferred compounds are the nitrate, oxalate and perchlorate salts. It is also possible to use mixtures of several such compounds. The following salts are mentioned by way of example: barium nitrate, strontium nitrate, barium oxalate, strontium oxalate, sodium oxalate and potassium perchlorate. Copper carbonate or copper oxide may also be used as the colouring component.

Compositions embodying this invention are prepared and used in tracer shells in exactly the same way as conventional tracer compositions.

After the individual components have been mixed, they are packed into shell casings in dry form under a pressure of from 2(K) to 10,000 atms. A tracer igniter is then pressed on. The tracer igniter can be of conventional type, and is preferably one based on a metal oxide (for example Pro2) and zirconium.

The following Example illustrates the invention.

EXAMPLE 22 parts by weight of finely powdered magnesium (grain size less than 45 ,a),10 parts by weight of zirconium powder, 2 parts by weight of potassium chlorate, 33 parts by weight of strontium nitrate and 33 parts by weight of calcium tetrachlorophthalate were thoroughly mixed and packed in dry form under a pressure of 55() kp in a shell casing having an axial bore with a diameter of 3.0 mm.

An ignition charge consisting of a mixture of 6 mg of zirconium and 9 mg of lead oxide was then pressed onto this composition. When the shell was fired, the tracer composition, ignited satisfactorily and burned uniformly, leaving a clearly visible trace throughout the trajectory of the shell.

WHAT WE CLAIM IS: 1. A tracer composition for producing a coloured trace, which comprises, in admixture and in particulate form, a lightweight metal, one or more oxygen-containing compounds of one or more alkali metals and/or alkaline earth metals and/or copper, metallic zirconium and a salt of a halogentated aromatic carboxylic or sulphonic acid.

2. A composition as claimed in Claim 1, which contains from 5 to 25% by weight of zirconium metal.

3. A composition as claimed in Claim 2, which contains from 8 to 13% by weight of zirconium metal.

4. A composition as claimed in any one of the preceding Claims, in which the zirconium metal has a particle size of from 0.001 to 0.04 mm.

5. A composition as claimed in Claim 4, in which the zirconium metal has a particle size of from 0.002 to 0.01 mm.

6. A composition as claimed in any one of the preceding Claims, in which the halogenated aromatic carboxylic acid is a mononuclear aromatic dicarboxylic acid chlorinated on the nucleus.

7. A composition as claimed in any one of the preceding Claims, in which the halogenated aromatic carboxylic or sulphonic acid salt is an alkali metal or alkaline earth metal salt.

8. A composition as claimed in Claim 7, in which the halogenated carboxylic or sulphonic acid salt is/calcium salt.

9. A composition as claimed in any one of the preceding Claims, which contains from 15 to 40% by weight of the halogenated aromatic carboxylic or sulphonic acid salt.

10. A composition as claimed in Claim 9.

which contains from 20 to 30% by weight of the halogenated aromatic carboxylic or sulphonic acid salt.

11. A composition as claimed in any one of the preceding Claims, which is free from a chlorine-containing organic binder of the type referred to herein.

12. A composition as claimed in any one of the preceding Claims, in which the lightweight metal is magnesium.

13. A composition as claimed in any one of the preceding Claims, in which the oxygencontaining compound is a nitrate. oxalate or perchlorate of an alkali metal or alkaline earth metal or copper carbonate or copper oxide.

14. A tracer composition. substantially as described in the foregoing Example.

15. A small calibre tracer shell which comprises a tracer composition as claimed in any one of the preceding Claims.

16. A shell as claimed in Claim 15. which has an axial bore having a diameter of not more than 4 mm.

17. A shell as claimed in Claim 15 or 16.

which comprises an igniter composition comprising a metal oxide and zirconium.

18. A small bore tracer shell, substantially as described in the foregoing Example.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

the colouring component.

Compositions embodying this invention are prepared and used in tracer shells in exactly the same way as conventional tracer compositions.

After the individual components have been mixed, they are packed into shell casings in dry form under a pressure of from 2(K) to 10,000 atms. A tracer igniter is then pressed on. The tracer igniter can be of conventional type, and is preferably one based on a metal oxide (for example Pro2) and zirconium.

The following Example illustrates the invention.

EXAMPLE

22 parts by weight of finely powdered magnesium (grain size less than 45 ,a),10 parts by weight of zirconium powder, 2 parts by weight of potassium chlorate, 33 parts by weight of strontium nitrate and 33 parts by weight of calcium tetrachlorophthalate were thoroughly mixed and packed in dry form under a pressure of 55() kp in a shell casing having an axial bore with a diameter of 3.0 mm.

An ignition charge consisting of a mixture of 6 mg of zirconium and 9 mg of lead oxide was then pressed onto this composition. When the shell was fired, the tracer composition, ignited satisfactorily and burned uniformly, leaving a clearly visible trace throughout the trajectory of the shell.

WHAT WE CLAIM IS: 1. A tracer composition for producing a coloured trace, which comprises, in admixture and in particulate form, a lightweight metal, one or more oxygen-containing compounds of one or more alkali metals and/or alkaline earth metals and/or copper, metallic zirconium and a salt of a halogentated aromatic carboxylic or sulphonic acid.
2. A composition as claimed in Claim 1, which contains from 5 to 25% by weight of zirconium metal.
3. A composition as claimed in Claim 2, which contains from 8 to 13% by weight of zirconium metal.
4. A composition as claimed in any one of the preceding Claims, in which the zirconium metal has a particle size of from 0.001 to 0.04 mm.
5. A composition as claimed in Claim 4, in which the zirconium metal has a particle size of from 0.002 to 0.01 mm.
6. A composition as claimed in any one of the preceding Claims, in which the halogenated aromatic carboxylic acid is a mononuclear aromatic dicarboxylic acid chlorinated on the nucleus.
7. A composition as claimed in any one of the preceding Claims, in which the halogenated aromatic carboxylic or sulphonic acid salt is an alkali metal or alkaline earth metal salt.
8. A composition as claimed in Claim 7, in which the halogenated carboxylic or sulphonic acid salt is/calcium salt.
9. A composition as claimed in any one of the preceding Claims, which contains from 15 to 40% by weight of the halogenated aromatic carboxylic or sulphonic acid salt.
10. A composition as claimed in Claim 9.

which contains from 20 to 30% by weight of the halogenated aromatic carboxylic or sulphonic acid salt.
11. A composition as claimed in any one of the preceding Claims, which is free from a chlorine-containing organic binder of the type referred to herein.
12. A composition as claimed in any one of the preceding Claims, in which the lightweight metal is magnesium.
13. A composition as claimed in any one of the preceding Claims, in which the oxygencontaining compound is a nitrate. oxalate or perchlorate of an alkali metal or alkaline earth metal or copper carbonate or copper oxide.
14. A tracer composition. substantially as described in the foregoing Example.
15. A small calibre tracer shell which comprises a tracer composition as claimed in any one of the preceding Claims.
16. A shell as claimed in Claim 15. which has an axial bore having a diameter of not more than 4 mm.
17. A shell as claimed in Claim 15 or 16.

which comprises an igniter composition comprising a metal oxide and zirconium.
18. A small bore tracer shell, substantially as described in the foregoing Example.