Draft Of Bullet 30 Mm Nato

1. General a. The term "cartridge identification" can cmbrace a wide span of activities, ranging from the simple determination of a cartridge's designation in terms of iti caliber and case length to a more complex analysis that can include its country of origin, functional type, model or type designation, and even tot number, year, and pJace of manufacture. This guide is generally limited in scope to cartridge designation and country and year of manufacture (though some data are provided on the identification of functional types and, for major producing countries, on the principal model or type designation) for cartridges in calibers of 15 mm and below. This breakoff point was selected because cartridges in this caliber range are predominantly of the small-arms type, having bullets of relatively simple construction with, typically, a bullet jacket and a core. Cartridges of 20-mm and greater calibers, on the other hand, generally have arriJIery-type projectiles, either fuzed explosive types or solid monobloc projectiles with artillery-type rotating bands. There arc at present no service types of military ammunition between 15 mm and 20 mm.

b. The problems involved in the identification of cartridges may be summarized in three questions, which this guide is designed to answer:

(1) What is the cartridge designation? This is expressed by a brief nomenclature, which includes a caliber (bullet diameter) measurement, that is applicable to all cartridges that were designed for, or arr suitable for use in, guns chambered for this specific cartridge.

(2) Who made the cartridge, and when? Normally this information can be derived frum the markings that appear on the cartridge base, which arc termed "headlamps." If the cartridge is unmarked, or if the markings are for any reason inadequate, it may be neccssary to make a detailed examination and comparison with similar cartridges of known origin. Dccause of its technical complexity, such a comparison falls outside the scope of this guide; fortunately, such examples are relatively uncommon,

(3) What is its functional type: ball, tracer, incendiary, or even explosive? This identification involves color codes, stamped markings, or bullet shapes; these are often unique to the country of manufacture and, furthermore, may vary with the time period in which the cartridge was produced.

c. Some of the military cartridge types that are described in this guide have been produced for many years. Cartridges made during and even before World War IJ are not necessarily unserviceable because of their age; if they have been stored under favorable conditions of low humidity and low to moderate temperature, and if the brass cartridge case has not become brittle from exposure to the mercuric compounds in the primer, or from improper annealing of the metal« thry may function quite reliably. Serviceability must be determined through inspection and testing by qualified ammunition specialists.

2. Organization

This guide comprises four major sections and two appendixes, with coverage as follows:

a. Section I outlines the scope of this guide and its organization. It also provides rhe gencrJ information on construction, characteristics, and terminology of small-arms cartridges that is essential for the effective utilization of this guide.

b. Section U provides instructions on the use of this guide in the identification of cartridges from dimensional and visual data.

c. Section III provides a series of outline drawings of cartridge cases: a tabulation of major cartridge dimensions; and a brief description of each cartridge type in terms of its origin, performance, using weapons, principal countries of manufacture and use, and current status. Cross-reference of information in these three areas is facilitated by the use of an index number that is assigned to each cartridge designation.

d. Section IV approaches the identification problem on a country-by-country basis. For cach country the following information is provided where applicable:

• Headstamp practices.

• Functional type identification.

• Package markings.

• Glossary of small-arms terms.

e. Appendix I provides a reference set of approximately 650 headstamp markings that are representative of several thousand variant types. These are presented in four annexes: handstamps that contain Western (Roman) letters; hcadstamps with Cyrillic. Greek, Arabic, or Hebrew letters; hcadstamps with Oriental characters or miscellaneous symbols as a major feature: and hcadstamps containing primarily Western numerals.

f. Appendix II provides limited identification data on 11 additional military cartridges, the use of which within the last 50 years has been too limited to justify their inclusion in section III.

3. Cartridge Cases

The primary feature in cartridge identification is the cartridge case. Its shape and dimensions, which must conform to the chamber size of the gun for which it is designed, indicate the type and probable military role of the weapon, which in tum may suggest the country of origin or the political inclinations of the user. From a supply point of view, the ease is the most expensive as well as, normally, the heaviest component of the cartridge. Basically the cartridge ease provides a reusable, waterright container for the primer, propcllant. and bullet. Functionally the cartridge ease serves several purposes; in particular, it provides a pressure seal in the gun chamber and serves as a heat sink to rid the gun of some of the heat generated during firing. Key aspects of cartridge-case design and construction are outlined in the following subparagraphs.

a. To provide desired performance characteristics, military cartridge cases must be robust; all are of centerfire construction, with a reinforced cartridge case head with a centrally located primer that initiates the propellant contained in the cartridge case. Case materials include bras*, mild steel (either plated or lacquered), and aluminum; of these a brass alloy, typically about 70% coppcr. is predominant. Gases are manufactured by punch-and-die operations, termed "drawing," with heat treatment to provide desired metallurgical characteristics.

b. Primers for small-arms cartridges are with rare exceptions (for aircraft machincgun use in World War II) of the percussion type, initiated by the impact of a firing pin. Two types of percussion priming are in use, the Boxer and the Berdan primer. The United States, as well as some other countries that utilize US-made production machinery, uses the Boxer primer (which, incidentally, was invented by a British army officer). The Boxer primer consists of a primer cup containing a priming mixture and an integral anvil; the primer seat in the cartridge base is ilat-bottomcd with, normally, one axial flash hole. The Berdan primer, named after a US army officcr, is predominant in the United Kingdom and Europe; the primer is a simple cup containing the priming mixture, while the anvil is formed as a part of the cartridge case. The Berdan primer normally has two flash holes, 180° apart, on either side of the anvil; a single offcenter hole has also been used with the intent of improving ignition by increasing the intensity of the primer flash. No functional difference between the two types has been noted; many cartridges, such as the 7.62x51 NATO cartridge, may have cither type, depending on the country of production. Figure 1 illustrates both types. Electric primers, which require an external current source of 24 to 28 V dc, were used by Germany in World War II on some 13x64B and 15x96 aircraft machincgun cartridges. Electric primers can be identified by the presence of an insulating ring around the primer.

Draft Bullet Nato

BOXER TYPE PRIMER BERDAN TYPE PRIMER

Figure 1. Small-arms cartridge primers.

c. Cartridge base type*, which serve a functional purpose in feeding and indexing the cartridge in the weapon, arc valuable identifying features. The five types-rimmed, semirimmed, rimless, rebated, and belted-are illustrated in figures 2 through 6.

(1) Rimmed cartridge cases have a rim, or extractor flange, that extends beyond the cartridge body. Some rimmed cartridges, such as the 9x29R (J8 Special; may also have a groove in the case body ahead of the rim (fig 2).

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