A shotgun shell, shotshell or simply shell is a type of
rimmed,
cylindrical
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
(straight-walled)
cartridges used specifically in
shotgun
A shotgun (also known as a scattergun, or historically as a fowling piece) is a long-barreled firearm designed to shoot a straight-walled cartridge known as a shotshell, which usually discharges numerous small pellet-like spherical sub- pr ...
s, and is typically loaded with numerous small,
pellet-like spherical sub-
projectile
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in ...
s called
shot, fired through a
smoothbore
A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.
History
Early firearms had smoothly bored barrels that fired projectiles without sign ...
barrel
A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...
with a
tapered constriction at the muzzle to regulate the extent of
scattering. A shell can sometimes also contain only a single large solid projectile known as a
slug
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...
, fired usually through a
rifled
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pr ...
slug barrel
A slug barrel is a shotgun barrel that is designed primarily to fire slugs instead of shot, and is usually rifled. A shotgun with such a barrel is often called a slug gun.
Origins
When slugs are fired in a standard, choked barrel, the slug is de ...
. The
hull
Hull may refer to:
Structures
* Chassis, of an armored fighting vehicle
* Fuselage, of an aircraft
* Hull (botany), the outer covering of seeds
* Hull (watercraft), the body or frame of a ship
* Submarine hull
Mathematics
* Affine hull, in affi ...
usually consists of a
paper or
plastic tube often covered at the base by a metallic head cover which retains a
primer
Primer may refer to:
Arts, entertainment, and media Films
* ''Primer'' (film), a 2004 feature film written and directed by Shane Carruth
* ''Primer'' (video), a documentary about the funk band Living Colour
Literature
* Primer (textbook), a te ...
, and the shot charge is typically contained by a
wadding/
sabot inside the case. The
caliber
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore match ...
of the shotshell is known as its
gauge.
The projectiles are traditionally made of
lead, but other
metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typica ...
s such as
steel,
tungsten and
bismuth
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs na ...
are also used due to
restrictions on lead, or for performance reasons such as achieving higher shot velocities by reducing the mass of the shot charge. Other unusual projectiles such as saboted
flechettes,
rubber balls,
rock salt and
magnesium shards also exist. Slug shells can also be made with
specialty non-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than conventional ...
projectiles such as
rubber and
bean bag round
A bean bag round, also known by its trademarked name flexible baton round, is a type of baton round, fired from a shotgun, and used for less lethal apprehension of suspects.
Description
The bean bag round consists of a small fabric "pillow" ...
s.
Shotguns have an
effective range of about with
buckshot
A shotgun shell, shotshell or simply shell is a type of rimmed, cylindrical (straight-walled) cartridges used specifically in shotguns, and is typically loaded with numerous small, pellet-like spherical sub-projectiles called shot, fired throu ...
, with
birdshot
A shotgun shell, shotshell or simply shell is a type of rimmed, cylindrical (straight-walled) cartridges used specifically in shotguns, and is typically loaded with numerous small, pellet-like spherical sub-projectiles called shot, fired throu ...
, with slugs, and well over with saboted slugs in
rifled barrel
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the p ...
s.
Other rounds include:
*Ferret rounds: rounds designed to penetrate a thin barrier (e.g. a car door) and release a gas payload.
*Bolo rounds: two large lead balls attached by a wire.
*Piranha rounds: shells full of sharp tacks.
*
Dragon's breath rounds: shells full of incendiary chemicals that creates a
fireball
Fireball may refer to:
Science
* Fireball (meteor), a brighter-than-usual meteor
* Ball lightning, an atmospheric electrical phenomenon
* ''Bassia scoparia'', a plant species
Arts and entertainment Films
* '' The Fireball'', a 1950 film starring ...
/
flame
A flame (from Latin '' flamma'') is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density they ...
when discharged, and can ignite a flammable target at close range.
Most shotgun shells are designed to be fired from a
smoothbore
A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.
History
Early firearms had smoothly bored barrels that fired projectiles without sign ...
barrel, but dedicated shotguns with
rifled
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pr ...
barrels are limited to lead slugs or
sabot slugs as "shot" would be spread too wide by the rifling. A rifled barrel will increase the accuracy of sabot slugs, but makes it unsuitable for firing shot, as it imparts a spin to the shot cup, causing the shot cluster to disperse. A rifled slug uses rifling on the slug itself so it can be used in a smoothbore shotgun.
History
Early shotgun shells used brass cases, not unlike pistol and rifle cartridge cases of the same era. These brass shotgun hulls or cases closely resembled large rifle cartridges, in terms of both the head and primer portions of the shotgun shell, as well as in their dimensions. Card wads, made of felt, leather, and cork, as well as paperboard, were all used at various times.
Waterglass (Sodium silicate) was commonly used to cement the top overshot wad into these brass shell casings. No roll crimp or fold crimp was used on these early brass cases, although roll crimps were eventually used by some manufacturers to hold the overshot wad in place securely. The primers on these early shotgun shells were identical to pistol primers of the same diameter.
Starting in the late 1870s, paper hulls began replacing brass hulls. Paper hulls remained popular for nearly a century, until the early 1960s. These shotgun shells using paper hulls were nearly always roll crimped, although fold crimping also eventually became popular. The primers on these paper hull shotgun shells also changed from the pistol primers used on the early brass shotgun shells to a primer containing both the priming charge and an anvil, unlike rifle and pistol ammunition, making the shotgun shell primer taller. Card wads, made of felt and cork, as well as paperboard, were all used at various times, gradually giving way to plastic over powder wads, with card wads, and, eventually, to all plastic wads. Starting in the early 1960s, plastic hulls started replacing paper hulls for the majority of shotgun shells and by the 1980s, plastic hulls had become universally adopted.
Typical construction
Modern shotgun shells typically consist of a plastic hull, with the base covered in a thin brass or plated steel covering. As noted previously,
paper shells used to be common, and are still made, as are solid brass shells. Some companies have produced what appear to be all-plastic shells, although in these there is a small metal ring cast into the rim of the shell to provide strength. Often the more powerful loads will use "
high brass" shells, with the brass extended up further along the sides of the shell, while light loads will use "low brass" shells. The brass does not actually provide a significant amount of strength, but the difference in appearance provides shooters with a way to quickly differentiate between high and low powered ammunition.
The base of the shell is fairly thick to hold the large shotgun
primer
Primer may refer to:
Arts, entertainment, and media Films
* ''Primer'' (film), a 2004 feature film written and directed by Shane Carruth
* ''Primer'' (video), a documentary about the funk band Living Colour
Literature
* Primer (textbook), a te ...
, which is longer than primers used for
rifle and
pistol
A pistol is a handgun, more specifically one with the chamber integral to its gun barrel, though in common usage the two terms are often used interchangeably. The English word was introduced in , when early handguns were produced in Europe, a ...
ammunition. Modern
smokeless powders are far more efficient than the original
black powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). Th ...
used in shotgun shells, so very little space is actually taken by powder; shotguns use small quantities of double base
powders
A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and ''granular'' are sometimes used to distin ...
, equivalent to quick-burning pistol powders, with up to 50%
nitroglycerin. After the powder comes the
wadding or wad. The primary purpose of a wad is to prevent the shot and powder from mixing, and to provide a seal that prevents gas from blowing through the shot rather than propelling it. The wad design may also encompass a shock absorber and a cup that holds the shot together until it is out of the barrel.
A modern wad consists of three parts, the powder wad, the cushion, and the shot cup, which may be separate pieces or be one part. The powder wad acts as the gas seal (known as
obturation), and is placed firmly over the powder; it may be a
paper or plastic part. The cushion comes next, and it is designed to compress under pressure, to act as a shock absorber and minimize the deformation of the shot; it also serves to take up as much space as is needed between the powder wad and the shot. Cushions are almost universally made of plastic with
crumple zone
Crumple zones, crush zones, or crash zones are a structural safety feature used in vehicles, mainly in automobiles, to increase the time over which a change in velocity (and consequently momentum) occurs from the impact during a collision by a ...
s, although for game shooting in areas grazed by farm stock or wildlife biodegradable fiber wads are often preferred. The shot cup is the last part of the shell, and it serves to hold the shot together as it moves down the barrel. Shot cups have slits on the sides so that they peel open after leaving the barrel, allowing the shot to continue on in flight undisturbed. Shot cups, where used, are also almost universally plastic. The shot fills the shot cup (which must be of the correct length to hold the desired quantity of shot), and the shotgun shell is then
crimped, or rolled closed.
Sizes
Standard
Shotgun shells are generally measured by "
gauge", which is the weight, in fractions of a pound, of a pure
lead round ball that is the same diameter as the internal diameter of the barrel; in Britain and some other locations outside the United States the term "bore" is used with the same meaning.
This contrasts with rifles and handguns, which are almost always measured in "
caliber
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore match ...
", a measurement of the internal diameter of the barrel measured in millimeters or inches and, consequently, is approximately equal to the diameter of the projectile that is fired.
For example, a shotgun is called "12-gauge" because a lead sphere that just fits the inside diameter of the barrel weighs . This measurement comes from the time when early
cannons were designated in a similar manner—a "12 pounder" would be a cannon that fired a cannonball; inversely, an individual "12-gauge" shot would in fact be a pounder. Thus, a 10-gauge shotgun has a larger-diameter barrel than a 12-gauge shotgun, which has a larger-diameter barrel than a 20-gauge shotgun, and so forth.
The most popular shotgun gauge by far is 12-gauge. The larger 10-gauge, once popular for hunting larger birds such as goose and turkey, is in the decline with the advent of longer, "magnum" 12-gauge shells, which offer similar performance. The mid-size 20-gauge is also a very popular chambering for smaller-framed shooters who favor its reduced recoil, those hunting smaller game, and experienced trap and
skeet shooters
Skeet may refer to:
* Skeet shooting, a discipline of competitive clay pigeon shooting
** ISSF Olympic skeet, a variant used at the Olympic Games
People
* Skeet Childress (born 1979), American guitar player in the band Look What I Did
* Skeet Q ...
who like the additional challenge of hitting their targets with a smaller shot charge. Other less-common, but commercially available gauges are 16 and 28. Several other gauges may be encountered but are considered obsolete. The 4, 8, 24, and 32 gauge guns are collector items. There are also some shotguns measured by diameter, rather than gauge. These are the .410 (10.4mm), .380 (9mm), and .22 (5.5mm); these are correctly called "
.410 bore
The .410 bore is one of the smallest caliber of shotgun shell commonly available (along with the 9mm Flobert rimfire cartridge, and the less common .22 rimfire shot shell). A .410 bore shotgun loaded with shot shells is well suited for small g ...
", not ".410-gauge".
The .410 bore is the smallest shotgun size which is widely available commercially in the United States. For size comparison purposes, the .410, when measured by gauge, would be around 67- or 68-gauge (it is 67.62-gauge), The .410 is often mistakenly assigned 36-gauge. The 36 gauge was in fact a .360 diameter cartridge which was in length and is now obsolete.
Other calibers
Snake shot (AKA: bird shot, rat shot and dust shot) refers to
handgun and
rifle cartridges loaded with small
lead shot. Snake shot is generally used for shooting at snakes, rodents, birds, and other
pest at very close range. The most common snake shot cartridges are
.22 Long Rifle
The .22 Long Rifle or simply .22 LR or 22 (metric designation: 5.6×15mmR) is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of rifles, pistols, revolvers, smo ...
,
.22 Magnum
The .22 Winchester Magnum Rimfire, also called .22 WMR, .22 Magnum, .22 WMRF, .22 MRF, or .22 Mag, is a rimfire cartridge. Originally loaded with a bullet weight of delivering velocities in the range from a rifle barrel, .22 WMR is now loaded ...
,
.38 Special
The .38 Special, also commonly known as .38 S&W Special (not to be confused with .38 S&W), .38 Smith & Wesson Special, .38 Spl, .38 Spc, (pronounced "thirty-eight special"), or 9x29mmR is a rimmed, centerfire cartridge designed by Smith & ...
,
9×19mm Luger,
.40 Smith & Wesson,
.44 Special
The .44 Smith & Wesson Special, also commonly known as .44 S&W Special, .44 Special, .44 Spl, .44 Spc, (pronounced "forty-four special"), or 10.9x29mmR is a smokeless powder center fire metallic revolver cartridge developed by Smith & Wesson in 1 ...
,
.45 ACP
The .45 ACP ( Automatic Colt Pistol) or .45 Auto (11.43×23mm) is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it ...
, and
.45 Colt
The .45 Colt (11.43×33mmR), is a rimmed, straight-walled, handgun cartridge dating to 1872. It was originally a black-powder revolver round developed for the Colt Single Action Army revolver. This cartridge was adopted by the U.S. Army in 1 ...
.
Commonly used by hikers, backpackers and campers, snake shot is ideally suited for use in
revolvers and
derringer
A derringer is a small handgun that is neither a revolver nor a semi/ fully automatic pistol. It is not to be confused with mini-revolvers or pocket pistols, although some later derringers were manufactured with the pepperbox configuration. ...
s, chambered for
.38 Special
The .38 Special, also commonly known as .38 S&W Special (not to be confused with .38 S&W), .38 Smith & Wesson Special, .38 Spl, .38 Spc, (pronounced "thirty-eight special"), or 9x29mmR is a rimmed, centerfire cartridge designed by Smith & ...
and
.357 Magnum
The .357 Smith & Wesson Magnum, .357 S&W Magnum, .357 Magnum, or 9×33mmR as it is known in unofficial metric designation, is a smokeless powder cartridge with a bullet diameter. It was created by Elmer Keith, Phillip B. Sharpe, and Douglas B. ...
. Snake shot may not cycle properly in
semi-automatic pistols. Rifles specifically made to fire
.22 caliber .22 caliber, or 5.6 mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm).
Cartridges in this caliber include the very widely used .22 Long Rifle and .223 Remington / 5.56×45mm NATO.
.22 inch is also a popular ...
snake shot are also commonly used by farmers for
pest control
Pest control is the regulation or management of a species defined as a pest; any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range ...
inside of barns and sheds, as the snake shot will not shoot holes in the roof or walls, or more importantly injure livestock with a
ricochet. They are also used for airport and warehouse pest control.
Shot shells have also been historically issued to soldiers, to be used in standard issue rifles. The
.45-70 "Forager" round, which contained a thin wooden bullet filled with birdshot, was intended for hunting
small game
Game or quarry is any wild animal hunted for animal products (primarily meat), for recreation (" sporting"), or for trophies. The species of animals hunted as game varies in different parts of the world and by different local jurisdictions, thou ...
to supplement the soldiers' rations. This round in effect made the .45-70 rifle into a
small gauge shotgun
A shotgun (also known as a scattergun, or historically as a fowling piece) is a long-barreled firearm designed to shoot a straight-walled cartridge known as a shotshell, which usually discharges numerous small pellet-like spherical sub- pr ...
, capable of killing rabbits, ducks, and other small game.
During World War II, the United States military developed the
.45 ACP
The .45 ACP ( Automatic Colt Pistol) or .45 Auto (11.43×23mm) is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it ...
M12 and M15 shot shells cartridges. They were issued to pilots, to be used as foraging ammunition in the event that they were shot down. While they were best used in the
M1917 revolver
The M1917 Revolvers were six-shot, .45 ACP, large frame revolvers adopted by the United States Military in 1917, to supplement the standard M1911 pistol during World War I. There were two variations of the M1917, one made by Colt and the other b ...
s, the M15 cartridge would actually cycle the semi-automatic
M1911 pistols action.
Garden guns
Garden guns are smooth-bore firearms specifically made to fire
.22 caliber .22 caliber, or 5.6 mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm).
Cartridges in this caliber include the very widely used .22 Long Rifle and .223 Remington / 5.56×45mm NATO.
.22 inch is also a popular ...
snake shot, and are commonly used by gardeners and farmers for
pest control
Pest control is the regulation or management of a species defined as a pest; any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range ...
. Garden guns are short-range weapons that can do little harm past 15 to 20 yards, and they are quiet when fired with snake shot, compared to a standard ammunition. These guns are especially effective inside of barns and sheds, as the snake shot will not shoot holes in the roof or walls, or more importantly injure
livestock with a
ricochet. They are also used for pest control at airports, warehouses, stockyards, etc.
Shotgun gauge diameter formula
The standard definition of shotgun gauge assumes that a pure lead ball is used. The following formulas relate the bore diameter ''d
n'' (in inches) to the gauge ''n'':
: