AMMUNITION, MAGAZINES, AND MISSILE HANDLING
In the preceding chapter, you learned about the raw materials that are used to make up explosives and pyrotechnics. In this chapter, you will study Navy gun ammunition and its basic construction features and functions. We will identify the types of projectiles and fuzes used in the Navy and describe the systems used to identify ammunition. We will also describe magazines and their sprinkler and alarm systems. We discuss some of the equipment, training requirements, and safety precautions pertaining to the handling and stowage of ammunition. Finally, we will discuss missile processing and associated handling equipment. To get the most benefit from this chapter, you should have a basic understanding of the Navy's Maintenance and Material Management (3-M) System. You may wish to review the 3-M Systems fundamentals before continuing.
LEARNING OBJECTIVE Describe the classification, components, and features of Navy gun ammunition.
In a general sense, ammunition includes anything that is intended to be thrown at or put in the path of the enemy to deter, injure, or kill personnel or to destroy or damage materials. In this section, we describe how ammunition is classified, the common components of gun ammunition, and some of the types of gun ammunition in use today.
Gun ammunition is classified in several different ways, depending on your needs. It maybe classified by size of gun, assembly configuration, service use, or purpose and construction.
Classification by Size of Gun
Gun ammunition is most commonly classified by the size of the gun in which it is used. In addition to designations of bore diameter, such as 25-mm, 76-mm, or 5-inch, the length of the gun bore in calibers (inches) is also used as a means of classification. Thus a 5-inch, 54-caliber projectile is one used in a gun having a bore diameter of 5 inches and a bore length of 54 times 5 inches, or 270 inches.
Classification by Assembly
The three types of ammunition classified by assembly are shown in figure 2-1.
FIXED AMMUNITION.- The fixed class applies to ammunition that has the cartridge case crimped around the base of the projectile. The primer is assembled in the cartridge case. The projectile and the cartridge case, containing the primer and propellant charge, all form one unit as a fixed round of ammunition. Guns through 76-mm use fixed ammunition.
SEPARATED AMMUNITION.- This class applies to ammunition that consists of two units-the projectile assembly and the cartridge case assembly. The projectile assembly consists of the projectile body containing the load, nose fuze, base fuze, and auxiliary detonating fuze, as applicable. The cartridge case assembly consists of the cartridge case, primer, propellant charge, wad, distance piece, and a plug to close the open end of the cartridge case. The projectile and cartridge are rammed into the gun chamber together as one piece though they are not physically joined. Separate ammunition has been produced in gun sizes of 5-inch, 38-caliber through 8-inch, 55-caliber guns.
Figure 2-1.-Typical Navy gun ammunition assemblies.
SEPARATE-LOADING (BAGGED GUN) AMMUNITION.- This class applies to gun sizes 8 inches and larger. Separate-loading ammunition does not contain a cartridge case. The propellant charge is loaded in silk bags that are consumed during the combustion of the propellant when fired from the gun. The projectile, propellant charge, and primer are loaded separately. There are currently no naval guns in use that use separate-loading ammunition.
Classification by Service Use
For economy and safety, gun ammunition is assembled and classified by service use, as follows: Service: Ammunition for use in combat. These
exercises. The projectiles are comparable in weight and shape to those of service ammunition but are of less expensive construction and normally contain
no explosive. Variable time, nonfragmenting (VT NONFRAG) projectiles are an exception in that they are for training purposes and have a combination black powder-pyrotechnic color-burst element.
Dummy or Drill: Any type of ammunition assembled without explosives, or with inert material substituted for the explosives, to imitate service ammunition. The ammunition may be made of metal or wood. Dummy or drill ammunition is used in training exercises or in testing equipment. It is normally identified as dummy cartridges, dummy charges, or drill projectiles. Drill projectiles will not be fired from any gun.
Classification by Purpose and Construction
Service projectiles are classified by their tactical purpose as one of the following types: penetrating, fragmenting, and special purpose. Since targets differ in design and purpose, projectiles must also differ in their construction to make them more effective. If you were to cut open, for purposes of inspection, the different types of projectiles listed previously (other than small arms), you would find their construction and characteristics are common. For example, penetrating projectiles have thick walls and a relatively small cavity for explosives, while fragmenting projectiles are thin-walled and have a relatively large cavity for explosives. Because of this difference, projectiles may also classified by their construction.