Bullet

This article is about firearms projectiles. For other uses, see Bullet (disambiguation).
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, slingshot, 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.

Bullets fired from slings, slingshots, and many airguns (including BB guns) travel well below the speed of sound (about 343 m/s or 1126 ft/s in dry air at 20 °C or 68 °F). Low-power handguns have muzzle velocities generally less than the speed of sound (subsonic), while bullets fired from high-power handguns (such as a .44 Magnum) and from rifles have an initial speed faster than the speed of sound, meaning they are supersonic and thus can travel a substantial distance and even hit a target before a nearby observer hears the "bang" of the shot. Bullet speed through air depends on a number of factors such as barometric pressure, humidity, air temperature, and wind speed.[2][3]

History

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

The history of bullets far predates the history of firearms. For instance, ammunition for crossbows could have been spherical in addition to shooting crossbow bolts. In discussing astronomical topics such as solar and lunar eclipses, the Western-Han era Chinese mathematician and music theorist Jing Fang (78-37 BC) wrote that the moon, shaped like a ball, produced no light and was illuminated only by the sun, which he compared to the shape of a round crossbow bullet.[4] 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 that held the bullet firmly in the barrel and against the powder. (Bullets not firmly on the powder risked exploding the barrel, 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 have origins that almost pre-date civilization and were used by slingers in slings. They were typically made out of copper or lead. The most notable use of square bullet designs was done by, James Puckle and Kyle Tunis who patented them, where they were briefly used in one version of the Puckle gun. The early use of these in the black-powder era was soon discontinued due to irregular and unpredictable flight patterns.

Pointed bullets

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 that, on 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 similar to Norton's bullet, except that Greener fitted the hollow base of the bullet with a wooden plug that more reliably forced the base of the bullet to expand and catch the rifling. Tests proved that Greener's bullet was extremely effective, but the military rejected it too because, being two parts, they judged it as 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 small 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

.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 Lt. Colonel 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 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.

A ballistic tip bullet is a hollow-point rifle bullet that has a plastic tip on the end of the bullet itself. This improves external ballistics by streamlining the bullet, allowing it to cut through the air more easily, and improves terminal ballistics by allowing the bullet to act as a JHP on impact.

As a side effect, it also feeds better in weapons that have trouble feeding rounds that are not FMJ rounds.

Design

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 that forms this seal without 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 to place the center of mass of the bullet as far forward as is practical, which is how the Minié ball and the shuttlecock are designed. This makes the bullet 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, or break apart. For a given material and bullet, the strike velocity is the primary factor that determines 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,[5] 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

Propulsion of the ball can happen via several methods:

Materials

Expanding bullet loaded in a 6.5×55mm 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.

Hard cast solid bullet (left), with gas check (center) and lubrication (right).

Treaties and prohibitions

Poisonous bullets were a subject to an international agreement as early as the Strasbourg Agreement (1675).

The St. Petersburg Declaration of 1868 prohibited the use of explosive projectiles weighing less than 400 grams.[8]

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 that 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 ammunitions 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 acting on environmental concerns have banned hunting with lead bullets and shotgun pellets.[9]

In December 2014, a federal appeals court denied a lawsuit by environmental groups that the EPA must use the Toxic Substances Control Act to regulate lead in shells and cartridges. The groups sought to regulate "spent lead", yet EPA could not regulate spent lead without also regulating cartridges and shells, per the court.[10]

Bullet abbreviations

2F 2-part Controlled Fragmenting
ACC Remington Accelerator [11] (see sabot)
ACP Automatic Colt Pistol
AE Action Express
AGS African Grand Slam (Speer)
AP Armor Piercing (has a depleted uranium or other hard metal core)
APT Armor-piercing tracer
API Armor-piercing incendiary
APFSDS Armor-piercing Fin Stabilized Discarding Sabot round
B Ball
B2F Brass 2-part Fragmenting [12]
BBWC Bevel Base Wadcutter
BEB Brass Enclosed Base
BJHP Brass Jacketed Hollow Point
Blitz Sierra BlitzKing
BMG Browning Machine Gun
BrPT Bronze Point
Bt Boat-tail
BtHP Boat-tail Hollow Point
C2F Civilian 2-part Fragmenting [13]
CB Cast bullet
CL, C-L Remington 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)
DU Depleted Uranium
EFMJ Expanding Full Metal Jacket
EVO, FTX Hornady LEVERevolution Flex Tip eXpanding
EVO RWS Evolution bullet [14]
FMC Full Metal Case
FMJ Full Metal Jacket
FMJBT Full Metal Jacket Boat-Tail
FN Dangerous Game Solid Bullets Flat Nose
FNEB Flat Nose Enclosed Base
FP Flat Point
FP Full Patch
FST Winchester Fail Safe Talon
GAP (G.A.P.) Glock Automatic Pistol
GC Gas Check
GD Speer Gold Dot
GDHP Speer Gold Dot Hollow Point
GM Gilding Metal
GMCS Gilding Metal-Clad Steel
GS Remington Golden Saber
GSC GS Custom Turned Copper Bullets

HBWC Hollow Base Wadcutter
HC Hard Cast
HE-IT High Explosive Incendiary Tracer
HFN Hard Cast Flat Nose
HP Hollow Point
HPBT Hollow Point Boat Tail
HPCB Heavy Plate Concave Base
HPJ High Performance Jacketed
HS Federal Hydra-Shok
HST Federal Hi-Shok Two
HV Low friction Drive Band Bullets High Velocity
ID-Classic RWS fragmentation bullet, ex-TIG after Brenneke-license was not renewed.[15]
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
LF Lead Free
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
MK Sierra MatchKing
MRWC Mid-Range Wadcutter
MP Metal Point (only the tip of the bullet is covered)
NP Nosler Partition
OTM Open Tip Match
OWC Ogival Wadcutter [16]
P Practice, proof
PB Lead Bullet
PB Parabellum
PL Remington Power-Lokt
PnPT Pneumatic Point
PPL Paper patched lead
PSP Plated Soft Point
PSP, PTDSP Pointed Soft Point
PRN Plated Round Nose

RBT Rebated Boat Tail
RN Round Nose
RNFP Round Nose Flat Point
RNL Round Nosed Lead
SCHP Solid Copper Hollow Point
SJ Semi-Jacketed
SJHP Semi-Jacketed Hollow Point
SJSP Semi-Jacketed Soft Point
SLAP Saboted light armor penetrator
SP Soft Point
SP Spire Point
Sp, SPTZ Spitzer
SPC Special Purpose Cartridge
SpHP Spitzer Hollow Point
SST Hornady Super Shock Tip
SSp Semi-Spitzer
ST Silver Tip
STHP Silver Tip Hollow Point
SWC Semiwadcutter
SX Super Explosive
SXT Winchester Ranger Supreme Expansion Technology
T Tracer
TAG Brenneke lead-free bullet (German: Torpedo Alternativ-Geschoß)[17]
TBBC Carter/Speer Trophy Bonded Bear Claw soft point
TBSS Carter/Speer Trophy Bonded Sledgehammer Solid
TC Truncated Cone
THV Terminal High Velocity
TIG Brenneke fragmentation bullet (German: Torpedo Ideal-Geschoß)[18]
TMJ Total Metal Jacket
TNT Speer TNT
TUG Brenneke deformation bullet (German: Torpedo Universal-Geschoß)[19]
TOG Brenneke deformation bullet (German: Torpedo Optimal-Geschoß)[20]
UmbPT Umbrella Point
UNI-Classic RWS deformation bullet, ex-TUG after Brenneke-license was not renewed.[21]
VMAX Hornady V-Max
VLD Very Low Drag
WC Wadcutter
WFN Wide Flat Nose
WFNGC Wide Flat Nose Gas Check
WLN Wide Long Nose
X Barnes X-Bullet
XTP Hornady Extreme Terminal Performance

See also

References

  1. The Exploding Bullet Journal of Clinical Pathology
  2. https://www.youtube.com/watch?v=eneaN4h-qBs HOW fast bullet travels
  3. http://www.mythbusterstheexhibition.com/science-content/dodge-a-bullet/ DODGE A BULLET
  4. Needham, Joseph (1986). Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth. Taipei: Caves Books Ltd, p. 227.
  5. "RCBS". RCBS. Retrieved 2012-08-10.
  6. Hughes, David (1990). The History and Development of the M16 Rifle and Its Cartridge. Oceanside: Armory Pub. ISBN 978-0-9626096-0-2.
  7. "Research--Eagles and Lead.". SOAR Raptor Foundation.
  8. Glover, William H. "Purposes and Basic Principles of the Law of War". Retrieved 2010-07-28.
  9. "Nonlead Ammunition".
  10. Zack Colman (December 23, 2014). "EPA can't regulate lead bullets, says federal court". Washington Examiner. Retrieved 30 December 2014.
  11. "Bullet Basics 1- Materials; Remington Accelerator (at bottom of page)". Firearmsid.com. Retrieved 2012-08-10.
  12. Archived October 8, 2011, at the Wayback Machine.
  13. Archived January 3, 2012, at the Wayback Machine.
  14. "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Archived from the original on August 18, 2011. Retrieved 2012-08-08.
  15. "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Archived from the original on August 18, 2011. Retrieved 2012-08-08.
  16. BGB Enterprises. "Lead Bullets Technology - Premium Molds". Lbtmoulds.com. Retrieved 2012-08-10.
  17. "TAG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08.
  18. "TIG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08.
  19. "TUG". Brenneke-munition.de. Retrieved 2012-08-08.
  20. "TOG". Brenneke-munition.de. 2008-01-24. Retrieved 2012-08-08.
  21. "RWS | Rottweil: RWS | Rottweil". Jagd.rottweil-munition.de. Archived from the original on August 18, 2011. Retrieved 2012-08-08.
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