Explosives Used in Bullets Smokeless Powder

104 Pages·2011·4.7 MB·English

Revised Edition: 2016
ISBN 978-1-283-50519-2
© All rights reserved.
Published by:
White Word Publications
48 West 48 Street, Suite 1116,
New York, NY 10036, United States
Email: [email protected]
Table of Contents

Chapter 1 - Bullet

Chapter 2 - Hollow-Point Bullet

Chapter 3 - Expanding Bullet

Chapter 4 - Soft-Point Bullet & Plastic Tipped Bullets
Chapter 5 - Full Metal Jacket Bullet
Chapter 6 - Caliber
Chapter 7 - Explosives Used in Bullets
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Chapter 8 - Tracer Ammunition
Chapter 9 - Armor-Piercing Shot and Shell
Chapter 10 - Blank (Cartridge)

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Chapter 1
Bullet

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Lead soft-point, boat-tailed, copper-jacketed bullets
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally
contain explosives, but damage the intended target by impact and penetration. The word
"bullet" is sometimes used to refer to ammunition generally, or to a cartridge, which is a
combination of the bullet, case/shell, powder, and primer.
History

Lead sling bullets with a winged thunderbolt engraved on one side and the inscription
"Take that" on the other side. 4th century BC. From Athens.
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Matchlock mWusket balls, alleged to have been discoTvered at Naseby battlefield. From the
collection of Northampton Museum and Art Gallery.
The history of bullets far predates the history of firearms. Originally, bullets were
metallic or stone balls used in a sling as a weapon and for hunting.
Eventually as firearms were developed, these same items were placed in front of an
explosive charge of gun powder at the end of a closed tube. As firearms became more
technologically advanced, from 1500 to 1800, bullets changed very little. They remained
simple round (spherical) lead balls, called rounds, differing only in their diameter.
The development of the hand culverin and matchlock arquebus brought about the use of
cast lead balls as projectiles. "Bullet" is derived from the French word boulette which
roughly means little ball. The original musket bullet was a spherical lead ball smaller
than the bore, wrapped in a loosely-fitted paper patch which served to hold the bullet in
the barrel firmly upon the powder. (Bullets that were not firmly upon the powder upon
firing risked causing the barrel to explode, with the condition known as a short start.)
The loading of muskets was, therefore, easy with the old smooth-bore Brown Bess and
similar military muskets. The original muzzle-loading rifle, on the other hand, with a
more closely fitting ball to take the rifling grooves, was more difficult to load,
particularly when the bore of the barrel was fouled from previous firings. For this reason,
early rifles were not generally used for military purposes.
The first half of the nineteenth century saw a distinct change in the shape and function of
the bullet. In 1826, Delvigne, a French infantry officer, invented a breech with abrupt
shoulders on which a spherical bullet was rammed down until it caught the rifling
grooves. Delvigne's method, however, deformed the bullet and was inaccurate.
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Pointed bullets
Among the first pointed or "conical" bullets were those designed by Captain John Norton
of the British Army in 1823. Norton's bullet had a hollow base which upon firing
expanded under pressure to engage with a barrel's rifling. The British Board of Ordnance
rejected it because spherical bullets had been in use for the previous 300 years.
Renowned English gunsmith William Greener invented the Greener bullet in 1836. It was
very similar to Norton's bullet except that the hollow base of the bullet was fitted with a
wooden plug which more reliably forced the base of the bullet to expand and catch the
rifling. Tests proved that Greener's bullet was extremely effective but it too was rejected
for military use because, being two parts, it was judged as being too complicated to
produce.
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Minié ball ammunition
The soft lead Minié ball was first introduced in 1847 by Claude Étienne Minié (1814? –
1879), a captain in the French Army. It was nearly identical to the Greener bullet. As
designed by Minié, the bullet was conical in shape with a hollow cavity in the rear, which
was fitted with a little iron cap instead of a wooden plug. When fired, the iron cap would
force itself into the hollow cavity at the rear of the bullet, thereby expanding the sides of
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the bullet to grip and engage the rifling. In 1855, the British adopted the Minié ball for
their Enfield rifles.
The Minié ball first saw widespread use in the American Civil War. Roughly 90% of the
battlefield casualties in this war were caused by Minié balls fired from rifles.
Between 1854 and 1857, Sir Joseph Whitworth conducted a long series of rifle
experiments, and proved, among other points, the advantages of a smaller bore and, in
particular, of an elongated bullet. The Whitworth bullet was made to fit the grooves of
the rifle mechanically. The Whitworth rifle was never adopted by the government,
although it was used extensively for match purposes and target practice between 1857
and 1866, when it was gradually superseded by Metford's.
About 1862 and later, W. E. Metford carried out an exhaustive series of experiments on
bullets and rifling, and invented the important system of light rifling with increasing
spiral, and a hardened bullet. The combined result was that in December 1888 the Lee-
Metford small-bore (0.303", 7.70 mm) rifle, Mark I, (photo of cartridge on right) was
finally adopted for the British army. The Lee-Metford was the predecessor of the Lee-
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Enfield.
The modern bullet

.270 ammunition. Left to Right:
100-grain (6.5 g) – Hollow Point
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115-grain (7.5 g) – FMJBT
130-grain (8.4 g) – Soft point,
150-grain (9.7 g) – round nose.

.303 inch (7.7 mm) centrefire, FMJ rimmed ammunition
The next important change in the history of the rifle bullet occurred in 1882, when Major
Eduard Rubin, director of the Swiss Army Laboratory at Thun, invented the copper
jacketed bullet — an elongated bullet with a lead core in a copper jacket. It was also
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small bore (7.5mm and 8mm) and it is the precursor of the 8mm "Lebel bullet" which
was adopted for the smokeless powder ammunition of the Mle 1886 Lebel rifle.
The surface of lead bullets fired at high velocity may melt due to hot gases behind and
friction with the bore. Because copper has a higher melting point, and greater specific
heat capacity and hardness, copper jacketed bullets allow greater muzzle velocities.
European advances in aerodynamics led to the pointed spitzer bullet. By the beginning of
the twentieth century, most world armies had begun to transition to spitzer bullets. These
bullets flew for greater distances more accurately and carried more energy with them.
Spitzer bullets combined with machine guns greatly increased the lethality of the
battlefield.
The latest advancement in bullet shape was the boat tail, a streamlined base for spitzer
bullets. The vacuum created as air moves at high speed passes over the end of a bullet
slows the projectile. The streamlined boat tail design reduces this form drag by allowing
the air to flow along the surface of the tapering end. The resulting aerodynamic
advantage is currently seen as the optimum shape for rifle technology. The first
combination spitzer and boat-tail bullet, named Balle "D" from its inventor (a lieutenant-
colonel Desaleux) , was introduced as standard military ammunition in 1901, for the
French Lebel Model 1886 rifle .
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Design
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A modern cartridge consists of the following:
1. the bullet itself, which serves as the projectile;
2. the case, which holds all parts together;
3. the propellant, for example gunpowder or cordite;
4. the rim, part of the casing used for loading;
5. the primer, which ignites the propellant.
Bullet designs have to solve two primary problems. They must first form a seal with the
gun's bore. If a strong seal is not achieved, gas from the propellant charge leaks past the
bullet, reducing efficiency. The bullet must also engage the rifling without damaging the
gun's bore. Bullets must have a surface which will form this seal without causing
excessive friction. These interactions between bullet and bore are termed internal
ballistics. Bullets must be produced to a high standard, as surface imperfections can
affect firing accuracy.
The physics affecting the bullet once it leaves the barrel, is termed external ballistics. The
primary factors affecting the aerodynamics of a bullet in flight are the bullet's shape and
the rotation imparted by the rifling of the gun barrel. Rotational forces stabilize the bullet
gyroscopically as well as aerodynamically. Any asymmetry in the bullet is largely
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canceled as it spins. With smooth-bore firearms, a spherical shape was optimum because
no matter how it was oriented, it presented a uniform front. These unstable bullets
tumbled erratically and provided only moderate accuracy, however the aerodynamic
shape changed little for centuries. Generally, bullet shapes are a compromise between
aerodynamics, interior ballistic necessities, and terminal ballistics requirements. Another
method of stabilization is for the center of mass of the bullet to be as far forward as is
practical as in the Minié ball or the shuttlecock. This allows the bullet to fly front-forward
by means of aerodynamics.
Actual bullet shapes are many and varied, and an array of them can be found in any
reloading manual that sells bullet moulds. Mould manufacturers such as RCBS, Paul
Jones Moulds, and David Mos offer many different calibers and designs. With a mould,
bullets can be made at home for reloading one's own ammunition, where local laws
allow. Hand-casting, however, is only time- and cost-effective for solid lead bullets. Cast
and jacketed bullets are also commercially available from numerous manufacturers for
hand loading and are much more convenient than casting bullets from bulk lead.
Materials
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