II. Surf the Internet and find some other cases of casting defects. Make a note of them and bring your notes to the class. Unit VI I ammunition

Part I

I. Read the text and circle the information that is not mentioned in the text.

1) the purpose of ammunition

2) types of ammunition

3) storage of ammunition

4) naval ammunition

5) bullet design and manufacture

6) case design

7) cartridge assembly

8) raw material

9) supply ammunition in the field

10) modern ammunition

Ammunition is all material used for war. It covers anything that can be used in combat that includes bombs, missiles, warhead, and mines ( landmines, naval mines, and anti-personnel mines). The purpose of ammunition is to project force against a selected target. Ammunition is the projectiles and propelling charges used in small arms, artillery, and other guns. Ammunition size is usually expressed in terms of caliber, which is the diameter of the projectile as measured in millimeters or inches. In general, projectiles less than 20 mm or 60 inch in diameter are classified as small-arm, and larger calibers are considered artillery. A complete round of ammunition consists of all the components necessary for one firing of the gun.

Modern ammunition includes artillery and mortars and aircraft-delivered bombs, smart bombs, rockets and other explosive-bearing projectiles. The design of the ammunition is determined by its aim; anti-personnel ammunition is often designed to break up inside the target, in order to maximize the damage done. Anti-personnel shells contain shrapnel and are designed to explode in mid-air, so its fragments will spread over a large area.

The components of ammunition may be divided into these categories:

• explosives and propellants

• projectiles of all kinds

• cartridges

Small arms ammunition, or cartridges, are used in a variety of firearms ranging from pistols to rifles and shotguns to heavier automatic weapons sometimes called machine guns. The term “bullet” is commonly used to describe the cartridge, when in fact, it is the projectile. The correct terminology for the cartridge components are bullet, case, primer, and propellant or gunpowder. Each component is manufactured separately and then assembled into the cartridge. Bullets are made of a lead alloy, often containing tin and antimony. Some bullets have a thick jacket of copper over the outside for improved performance.

Cases are made of brass, steel, or aluminum. Brass is the most common. Shotgun shells are often made with a polypropylene plastic case attached to a metal base. Primers are made of a copper or brass alloy cup with a brass anvil and are filled with an impact-sensitive lead igniter. The metal parts of the primer are usually nickel-plated to resist corrosion.

Propellants can vary from black gunpowder to a more modern smokeless powder which contains nitrocellulose. Propellants are carefully formulated to ignite and create an expanding gas that accelerates the bullet down the barrel.

Bullets can be made by several different processes. Smaller 22 caliber bullets are usually lead and are pressed, or cold formed, into shape. A small piece of thick lead wire is cut to the correct length and formed into the bullet shape by a die set in an automatic press. Many handgun and rifle bullets used for competition shooting are cast using conventional casting methods. The molten lead is poured into the bullet mold cavity, cooled quickly, and then extracted from the mold. The point at which the lead enters the cavity is trimmed away as the bullet is extracted. Both cold-formed and cast bullets may be further improved by copper plating. The plating process electrically deposits a thin layer of copper on the outside of the bullet, protecting the lead from oxidation and providing a harder surface to engage the grooves or rifling in the barrel which give the bullet a spin to improve accuracy. To improve bullet performance and accuracy, the “jacketed” bullet was developed. This is a family of bullets that use a substantial brass or copper outer shell, usually filled with lead by casting or cold forming.

Specialized bullets are sometimes found in military applications. Armor-piercing bullets can be solid brass or copper jacketed steel core. These can penetrate engine blocks and aircraft frames, damaging mechanisms inside. Small arms ammunition cases are of brass alloy. Some use aluminum, steel, or plastic, but the brass case is most popular and easiest to manufacture.

The design of the case is determined by the firearm in which the ammunition is used. The typical brass case is formed from annealed sheet by drawing with a multiple punch and die set. The first stage of the multiple die set forms the metal, the second stretches the metal deeper, the third forms the rim, and so on. Each step stretches the metal slightly farther until the final stage produces an accurately formed case. Some handgun caliber cases are nickel plated for durability in reloading, corrosion resistance. Each case is stamped with information such as caliber, manufacturer, munitions codes, and year of manufacture.

The primer consists of two metal parts and a small amount of explosive compound. Primers come in different sizes depending on the firearm. Using a small pistol primer as an example, the cup is usually about 0.125 inch (0.32 cm) in diameter and 0.125 inch (0.32 cm) tall, and made of soft copper or brass. Inside is placed a small amount of the impact-sensitive explosive lead. When struck by the firing pin, the center of the cup collapses, squeezing the explosive between its inner surface and the anvil. The explosive ignites and shoots a flame through the flash hole, igniting the propellant to fire the cartridge.

This is how a typical center-fire metal cartridge is assembled:

• The cases are fed into a loading press which first sizes the case.

• The primer is then pressed into the case primer hole flush with the base. The primer must be flush or the cartridge will not feed properly in the weapon magazine, causing a “jam”.

• The case is “charged”, or filled with the correct amount of propellant. This step is important, for miscalculation or double charging could be disastrous.

• The bullet is firmly seated into the open end of the case. The bullet has a coating of lubricant to prevent corrosion and assist in the assembly process. The bullet is then crimped into the case to give the correct overall length of the cartridge. The crimp reduces the diameter of the open end of the case and captures the bullet tightly, sealing the assembly together so moisture cannot invade the powder.

The press used to assemble cartridges must feed each component accurately and in the correct sequence. Otherwise, cases could be unprimed, powder left out, or bullets seated incorrectly . Any of these could result in a misfire or loss of accuracy. After assembly, the finished cartridges are packaged, usually 50 to a box, and prepared for shipment to the shooter.

Most manufacturers shoot thousands of their own cartridges as part of their quality control programs and processes. The accuracy, pressure, reliability, velocity, and consistency are all recorded. Each production run of a particular cartridge is given a “lot code”. This number, printed on the ammunition box, allows ammunition to be inventoried and traced. Should a particular lot show problems in the field, that group can be recalled and replaced.

II. Match the words with the Russian equivalents:

1) pistol a) патрон

2) hand gun, machine gun b) пистолет

3) rifle n.,v. c) подрезать

4) shooting d) пулемет

5) case e) извлекать

6) mold f) винтовка, нарезать канал ствола

7) lead g) прочность, долговечность

8) extract h) свинец

9) trim away i) стрельба

10) accuracy j) точность

11) shell k) дробовик

12) shotgun l) гильза

13) firearm, weapon m) отливать, формовать

14) durability n) огнестрельное оружие

15) primer o) снаряд

16) cartridge р) запал

III. Look at the groups of words below. Which is the odd one out in each group?

1) a. shell b. cartridge c. round d. bullet

2) a. handgun b. firearm c. shotgun d. rifle

3) a. break up b. damage c. explode d. divide

4) a. personnel b. antimony c. brass d. polypropylene

5) a. annealed b. determined c. stretched d. squeezed

6) a. bullet b. case c. primer d. cartridge

7) a. missile b. combat c. warhead d. mine

8) a. shotgun b. bomb c. mortar d. rocket

IV. Find the word in the text that has the similar meaning to the following:

1) weapon

2) fight

3) embrace

4) purpose

5) missile

6) molding

7) produce

8) fuel

V. Match the words with their definitions:

1) ammunition a) smth to be sent forward from a gun

2) combat b) smth to be aimed at in shooting practice

3) missile c) a container for bullets

4) target d) a case containing explosive with a bullet

5) explode e) a shaped piece of lead fired from a rifle

6) propellant f) anything that can be used in combat

7) projectile g) fight, struggle

8) cartridge h) to destroy

9) bullet i) an object or a weapon that is thrown ( a stone), shot (an arrow),

projected ( a rocket)

10) case j) smth used to produce forward motion

VI. Are the following statements true or false? Correct the false ones with the right information and discuss your answer with your partner.

1) Ammunition is a tool used only in hunting.

2) In attack ammunition projects force against a target.

3) Modern ammunition includes mortars, smart bombs, shotguns and rockets.

4) Anti-personnel ammunition is designed to penetrate engine blocks, damaging mechanisms inside.

5) The term bullet is used to describe the cartridge.

6) A cartridge consists of a bullet, a case, a primer and propellant.

7) Bullets can be made by one process, by casting.

8) Copper plating improves bullets.

9) The most popular small arms ammunition cases are of brass alloy.

10) After assembly, the finished cartridge are stamped with information such as caliber and manufacture.

VI I. Work in pairs. Discuss which sentence in B best continues the sentence in A.

A B.

1) Ammunition is a) two metal parts and some explosive compound.

2) The purpose of ammunition is b) poured into the bullet mold cavity, cooled and extracted.

3) The components of ammunition c) formed from annealed sheet.

may be

4) Bullets are made of d) anything that can be used in a combat.

5) Cases are made of e) to project force against a selected target.

6) A piece of thick lead wire f) of brass alloy.

7) A brass case is g) explosives, projectiles and cartridges.

8) The molten lead is h) brass, steel, or aluminum.

9) Ammunition cases are i) a lead alloy.

10) A primer consists of j) cut and formed into a bullet shape.

VIII. What do these numbers refer to?

20, 22, 60, 0.125, 50

Talk about ammunition from memory using these prompts.

used in combat

the purpose of ammunition

modern ammunition

components of ammunition

bullets

cases

primers

cartridges

Part II

You are going to read the texts about three different firearms. For questions 1–10 choose from the firearms (A–C). There may be more than one answer.

Which firearm

• is fired from the shoulder?

• is used in sports?

• is different from a rifle and a machine gun?

• is the simplest firearm?

• is the heaviest firearm?

• is popular among security guards?

• fires in quick succession?

• is mounted on a vehicle?

• is named after people?

Which article describes the development of firearms?

Text A

Revolver

A revolver is a repeating firearm that consists of multiple chambers and at least one barrel for firing. As the user cocks the hammer, the cylinder revolves to align the next round with the barrel, which gives this type of firearm its name. In modern revolvers, the revolving cylinder typically chambers 5 or 6 rounds.

A single action revolver requires the hammer to be pulled back by hand before each shot. In contrast, in a double action revolver, squeezing the trigger can pull back the hammer to cock the gun as well as serving to release the hammer. Most modern double action revolvers can also be fired in single action mode, which serves to improve the accuracy by reducing the force and distance required to pull the trigger.

Compared to autoloading handguns, a revolver is often simpler to operate (despite often being more mechanically complex) and may have greater reliability (depending on firmness of grip, ammunition or cartridge used, and degree of maintenance and lubrication provided to the firearm). Their lower ammunition capacities and relatively longer reload times compared to autoloading pistols are the main reasons for the switch over that occurred in the 1980s and 1990s. Revolvers still remain popular among American law enforcement officers and security guards. Also, revolvers are still common in the American private sector as defensive and sporting/hunting firearms.

As a general rule, revolvers cannot be equipped with a sound suppressor , as there is usually a small gap between the revolving cylinder and the barrel over which a bullet must backward to extract the fired case.