Bullet

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A modern cartridge consists of the following:
1. the bullet, as the projectile;
2. the case, which holds all parts together;
3. the propellant, for example gunpowder or cordite;
4. the rim, which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired;
5. the primer, which ignites the propellant.
Schlieren image of a bullet travelling in free-flight demonstrating the air pressure dynamics surrounding the bullet.

A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives,[1] but damage the intended target by impact and penetration. The word "bullet" is sometimes colloquially used to refer to ammunition in general, or to a cartridge, which is a combination of the bullet, case/shell, powder, and primer. This use of 'bullet', when 'cartridge' is intended, leads to confusion when the components of a cartridge are discussed or intended. See the reference section for more detail.

History[edit]

Lead sling bullets, ca. 100 g with a winged thunderbolt engraved on one side and the inscription "Take that" (ΔΕΞΑΙ) on the other side. Athens, 4th century BC.

The history of bullets far predates the history of firearms. Originally, bullets were made out of stone or purpose-made clay balls used as sling ammunition, as weapons and for hunting. Eventually as firearms were developed, these same items were placed in front of a propellant charge of gunpowder 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.

Matchlock musket balls, alleged to have been discovered at Naseby battlefield.

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.

Square bullets, invented by James Puckle and Kyle Tunis, were briefly used in one version of the Puckle gun. The use of these was soon discontinued due to irregular and unpredictable flight patterns.

Pointed bullets[edit]

This bullet mold was designed for use with the .44 caliber Colt Army Model 1860 revolver. The mold includes chambers for casting round balls and conical Minié ball. This mold is from the collection of the Minnesota Historical Society.

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.[citation needed]

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.

Minié ball ammunition

The soft lead Minié ball was first introduced in 1847 by Claude-Étienne Minié, 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, thus expanding the sides of the bullet to grip and engage the rifling. In 1855, the British adopted the Minié ball for their Enfield rifles. A similar bullet called the Nessler ball was also developed for smoothbore muskets.

The small 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, was finally adopted for the British army. The Lee-Metford was the predecessor of the Lee-Enfield.

The modern bullet[edit]

.270 ammunition. Left to right:
100-grain (6.5 g) – hollow point
115-grain (7.5 g) – FMJBT
130-grain (8.4 g) – soft point
150-grain (9.7 g) – round nose

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 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.

.303 inch (7.7 mm) centrefire, FMJ rimmed ammunition

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 moving 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 .

Design[edit]

A bullet in mid flight

Bullet designs have to solve two primary problems. In the barrel, 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, thus reducing efficiency and possibly accuracy. The bullet must also engage the rifling without damaging or excessively fouling the gun's bore, and without distorting the bullet, which will also reduce accuracy. 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 canceled as it spins. However, a spin rate greater than the optimum value adds more trouble than good, by magnifying the smaller asymmetries or sometimes resulting in the bullet exploding midway in flight. 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, which is how the Minié ball and the shuttlecock are designed. This allows the bullet to fly front-forward by means of aerodynamics.

See the articles on terminal ballistics and/or stopping power for an overview of how bullet design affects what happens when a bullet impacts with an object. The outcome of the impact is determined by the composition and density of the target material, the angle of incidence, and the velocity and physical characteristics of the bullet itself. Bullets are generally designed to penetrate, deform, and/or break apart. For a given material and bullet, the strike velocity is the primary factor determining which outcome is achieved.

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,[2] 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.

Propulsion[edit]

Propulsion of the ball can happen via several methods:

Materials[edit]

Expanding bullet loaded in a 6.5x55mm before and after expanding. The long base and small expanded diameter show that this is a bullet designed for deep penetration on large game. The bullet in the photo traveled more than halfway through a moose before coming to rest, performing as designed.

Bullets for black powder, or muzzle loading firearms, were classically molded from pure lead. This worked well for low speed bullets, fired at velocities of less than 450 m/s (1475 ft/s). For slightly higher speed bullets fired in modern firearms, a harder alloy of lead and tin or typesetter's lead (used to mold Linotype) works very well. For even higher speed bullet use, jacketed coated lead bullets are used. The common element in all of these, lead, is widely used because it is very dense, thereby providing a high amount of mass—and thus, kinetic energy—for a given volume. Lead is also cheap, easy to obtain, easy to work, and melts at a low temperature, which results in comparatively easy fabrication of bullets.

Lead alloy bullets as cast (left), with gas check (center) and lubricated (right).

Treaties and prohibitions[edit]

The St. Petersburg Declaration of 1868 prohibited the use of explosive projectiles weighing less than 400 grams.[5]

The Hague Convention prohibits certain kinds of ammunition for use by uniformed military personnel against the uniformed military personnel of opposing forces. These include projectiles which explode within an individual, poisoned and expanding bullets.

Protocol III of the 1983 Convention on Certain Conventional Weapons, an annexe to the Geneva Conventions, prohibits the use of incendiary munitions against civilians.

Nothing in these treaties prohibits tracers or the use of prohibited bullets on military equipment.

These treaties apply even to .22 LR bullets used in pistols, rifles and machine guns. Hence, the High Standard HDM pistol, a .22 LR suppressed pistol, had special bullets developed for it during World War II that were full metal jacketed, in place of the soft-point and hollow-point bullets that are otherwise ubiquitous for .22 LR rounds.

Some jurisdictions are acting on environmental concerns and banning hunting with lead shotgun pellets. This creates issues for shooters because stainless steel pellets are considered to behave sub-optimally in flight compared to lead. The element bismuth is a safe alternative whose density is closer to lead than steel, and ammunition made from it is becoming ever more widely available.

Bullet abbreviations[edit]

2F – 2-part Controlled Fragmenting
ACCRemington Accelerator [6] (see sabot)
ACPAutomatic Colt Pistol
AE – Action Express
AGS – African Grand Slam (Speer)
APArmor Piercing (has a steel or other hard metal core)
APT – Armor-piercing tracer
API – Armor-piercing incendiary
APFSDSArmor-piercing Fin Stabilized Discarding Sabot round
B – Ball
B2F – Brass 2-part Fragmenting [7]
BBWC – Bevel Base Wadcutter
BEB – Brass Enclosed Base
BJHP – Brass Jacketed Hollow Point
BlitzSierra BlitzKing
BMGBrowning Machine Gun
BrPT – Bronze Point
Bt – Boat-tail
BtHP – Boat-tail Hollow Point
C2F – Civilian 2-part Fragmenting [8]
CBCast Bullet
CL, C-LRemington Core-Lokt
CN – Cupronicknel
CNCS – Cupronickel-Clad Steel
CTFB – Closed Tip Flat Base
DBBWC – Double bevel based wadcutter
DEWC – Double Ended Wadcutter
DGS – Dangerous Game Solid (Hornady)
DGX – Dangerous Game Expanding (Hornady)
DUDepleted Uranium
EFMJ – Expanding Full Metal Jacket
EVO, FTXHornady LEVERevolution Flex Tip eXpanding
EVORWS Evolution bullet [9]
FMC – Full Metal Case
FMJFull Metal Jacket
FMJBT – Full Metal Jacket Boat-Tail
FNDangerous Game Solid Bullets[dead link] Flat Nose
FNEB – Flat Nose Enclosed Base
FP – Flat Point
FP – Full Patch
FSTWinchester Fail Safe Talon
GAP (G.A.P.)Glock Automatic Pistol
GC – Gas Check
GDSpeer Gold Dot
GDHPSpeer Gold Dot Hollow Point
GM – Gilding Metal
GMCS – Gilding Metal-Clad Steel
GSRemington Golden Saber
GSCGS Custom Turned Copper Bullets
HBWC – Hollow Base Wadcutter
HC – Hard Cast
HE-IT – High Explosive Incendiary Tracer
HFN – Hard Cast Flat Nose
HPHollow Point
HPBT – Hollow Point Boat Tail
HPJ – High Performance Jacketed
HSFederal Hydra-Shok
HSTFederal Hi-Shok Two
HVLow friction Drive Band Bullets High Velocity
ID-ClassicRWS fragmentation bullet, ex-TIG after Brenneke-license was not renewed.[10]
I-T – Incendiary-Tracer
'IB – Interbond (Hornady)
J – Jacketed
JAP – Jacketed Aluminium Point
JFP – Jacketed Flat Point
JHC – Jacketed Hollow Cavity
JHP – Jacketed Hollow Point
JHP/sabot – Jacketed Hollow Point/sabot
JSP – Jacketed Soft Point
L – Lead
L-C – Lead Combat
L-T – Lead Target
LFN – Long Flat Nose
LFP – Lead Flat Point
LHP – Lead Hollow Point
LRN – Lead Round Nose
LSWC – Lead Semiwadcutter
LSWC-GC – Lead Semiwadcutter Gas Checked
LWC – Lead Wadcutter
LTC – Lead Truncated Cone
MC – Metal Cased
MHP – Match Hollow Point
MKSierra MatchKing
MRWC – Mid-Range Wadcutter
MP – Metal Point (only the tip of the bullet is covered)
NPNosler Partition
OTM – Open Tip Match
OWCOgival Wadcutter [11]
P – Practice, proof
PB – Lead Bullet
PBParabellum
PLRemington Power-Lokt
PnPT – Pneumatic Point
PPL – Paper patched lead
PSP – Plated Soft Point
PSP, PTDSP – Pointed Soft Point
PRN – Plated Round Nose
RN – Round Nose
RNFP – Round Nose Flat Point
RNL – Round Nosed Lead
SJ – Semi-Jacketed
SJHP – Semi-Jacketed Hollow Point
SJSP – Semi-Jacketed Soft Point
SPSoft Point
SP – Spire Point
Sp, SPTZSpitzer
SPC – Special Purpose Cartridge
SpHPSpitzer Hollow Point
SSTHornady Super Shock Tip
SSp – Semi-Spitzer
ST – Silver Tip
STHP – Silver Tip Hollow Point
SWCSemiwadcutter
SX – Super Explosive
SXTWinchester Ranger Supreme Expansion Technology
T – Tracer
TAGBrenneke lead-free bullet (German: Torpedo Alternativ-Geschoß)[12]
TBBC – Carter/Speer Trophy Bonded Bear Claw soft point
TBSS – Carter/Speer Trophy Bonded Sledgehammer Solid
TC – Truncated Cone
THV – Terminal High Velocity
TIGBrenneke fragmentation bullet (German: Torpedo Ideal-Geschoß)[13]
TMJ – Total Metal Jacket
TNT – Speer TNT
TUGBrenneke deformation bullet (German: Torpedo Universal-Geschoß)[14]
TOGBrenneke deformation bullet (German: Torpedo Optimal-Geschoß)[15]
UmbPT – Umbrella Point
UNI-ClassicRWS deformation bullet, ex-TUG after Brenneke-license was not renewed.[16]
VMAXHornady V-Max
VLDVery Low Drag
WCWadcutter
WFN – Wide Flat Nose
WFNGC – Wide Flat Nose Gas Check
WLN – Wide Long Nose
X – Barnes X-Bullet
XTPHornady Extreme Terminal Performance

See also[edit]

References[edit]

  1. ^ The Exploding Bullet Journal of Clinical Pathology
  2. ^ "RCBS". RCBS. Retrieved 2012-08-10. 
  3. ^ Hughes, David (1990). The History and Development of the M16 Rifle and Its Cartridge. Oceanside: Armory Pub. ISBN 978-0-9626096-0-2. 
  4. ^ "Research--Eagles and Lead.". SOAR Raptor Foundation. 
  5. ^ Glover, William H. "Purposes and Basic Principles of the Law of War". Retrieved 2010-07-28. 
  6. ^ "Bullet Basics 1- Materials; Remington Accelerator (at bottom of page)". Firearmsid.com. Retrieved 2012-08-10. 
  7. ^ [1][dead link]
  8. ^ [2][dead link]
  9. ^ "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Retrieved 2012-08-08. [dead link]
  10. ^ "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Retrieved 2012-08-08. [dead link]
  11. ^ BGB Enterprises. "Lead Bullets Technology - Premium Molds". Lbtmoulds.com. Retrieved 2012-08-10. 
  12. ^ "TAG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08. 
  13. ^ "TIG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08. 
  14. ^ "TUG". Brenneke-munition.de. Retrieved 2012-08-08. 
  15. ^ "TOG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08. 
  16. ^ "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Retrieved 2012-08-08. [dead link]

External links[edit]