Stock (firearm)

Stock (firearm)

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A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbow
Crossbow
A crossbow is a weapon consisting of a bow mounted on a stock that shoots projectiles, often called bolts or quarrels. The medieval crossbow was called by many names, most of which derived from the word ballista, a torsion engine resembling a crossbow in appearance.Historically, crossbows played a...

s though a crossbow stock is more properly referred to as a tiller. The stock provides a means for the shooter to firmly support the device and easily aim it. The stock also transmits recoil
Recoil
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...

 into the shooter's body.

History and etymology



The term stock in reference to firearms dates to 1571 is derived from the Germanic
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 word stoc, meaning tree trunk
Trunk (botany)
In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the...

, referring to the wooden nature of the gunstock.

Early hand cannons used a simple stick fitted into a socket in the breech end to provide a handle. The modern gunstock shape began to evolve with the introduction of the arquebus
Arquebus
The arquebus , or "hook tube", is an early muzzle-loaded firearm used in the 15th to 17th centuries. The word was originally modeled on the German hakenbüchse; this produced haquebute...

, a matchlock
Matchlock
The matchlock was the first mechanism, or "lock" invented to facilitate the firing of a hand-held firearm. This design removed the need to lower by hand a lit match into the weapon's flash pan and made it possible to have both hands free to keep a firm grip on the weapon at the moment of firing,...

 with a longer barrel and an actual lock mechanism, unlike the hand-applied match of the hand cannon. Firing a hand cannon requires careful application of the match while simultaneously aiming; the use of a matchlock handles the application of the slow match
Slow match
Slow match or match cord is the very slow burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, and petards...

, freeing up a hand for support. With both hands available to aim, the arquebus could be braced with the shoulder, giving rise to the basic gunstock shape that has survived for over 500 years. This greatly improved the accuracy of the arquebus, to a level that would not be surpassed until the advent of rifled barrels
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

.

Ironically, the stocks of muskets introduced during the European colonization of the Americas
European colonization of the Americas
The start of the European colonization of the Americas is typically dated to 1492. The first Europeans to reach the Americas were the Vikings during the 11th century, who established several colonies in Greenland and one short-lived settlement in present day Newfoundland...

 were repurposed as hand-to-hand war clubs
Club (weapon)
A club is among the simplest of all weapons. A club is essentially a short staff, or stick, usually made of wood, and wielded as a weapon since prehistoric times....

 by Native Americans
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 and First Nations
First Nations
First Nations is a term that collectively refers to various Aboriginal peoples in Canada who are neither Inuit nor Métis. There are currently over 630 recognised First Nations governments or bands spread across Canada, roughly half of which are in the provinces of Ontario and British Columbia. The...

 when fragile accessories
Flintlock
Flintlock is the general term for any firearm based on the flintlock mechanism. The term may also apply to the mechanism itself. Introduced at the beginning of the 17th century, the flintlock rapidly replaced earlier firearm-ignition technologies, such as the doglock, matchlock and wheellock...

 were damaged or scarce ammunition exhausted. Techniques for gunstock hand weapons are being revived by martial arts such as Okichitaw
Okichitaw
Okichitaw is a martial art based on the fighting techniques of the Plains Cree First Nations. It was founded and developed by Canadian martial artist, George J. Lépine.- Origins :In his youth, founder George J...

.

Anatomy of a gunstock


A gunstock is broadly divided into two parts (see above). The rear portion is the butt (1) and front portion is the fore-end (2). The butt is further divided into the comb (3), heel (4), toe (5), and grip (6). The stock pictured is a thumbhole (7) style.

Styles and features of stocks


The most basic breakdown of stock types is into one-piece and two piece stocks. A one piece stock is a single unit from butt to fore-end, such as that commonly found on bolt action rifles. Two piece stocks use a separate piece for the butt and fore-end, such as that commonly found on break open
Break open
A break-action firearm is one whose barrels are hinged, and rotate perpendicular to the bore axis to expose the breech and allow loading and unloading of ammunition. A separate operation may be required for the cocking of a hammer to fire the new round...

 shotguns, and lever-action
Lever-action
Lever-action is a type of firearm action which uses a lever located around the trigger guard area, to load fresh cartridges into the chamber of the barrel when the lever is worked. Most lever-action firearms are rifles, but lever-action shotguns and a few pistols have also been made...

 rifles and shotguns. Traditionally, two piece stocks were easier to make, since finding a wood blank suitable for a long one piece stock is harder than finding short blanks for a two piece stock.



The grip area is one that varies widely. A straight grip stock (A) proceeds smoothly from toe to the trigger, giving a nearly horizontal angle for the trigger hand, while a full grip stock (E) contains a separate piece for the grip, providing a near vertical angle for the trigger hand, and is commonly found on modern military rifles, such as the ubiquitous AK-47
AK-47
The AK-47 is a selective-fire, gas-operated 7.62×39mm assault rifle, first developed in the Soviet Union by Mikhail Kalashnikov. It is officially known as Avtomat Kalashnikova . It is also known as a Kalashnikov, an "AK", or in Russian slang, Kalash.Design work on the AK-47 began in the last year...

 and M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...

 families of assault rifle
Assault rifle
An assault rifle is a selective fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles are the standard infantry weapons in most modern armies...

s. The semi-grip (B) stock is perhaps the most common sporting stock, with a steeper angle cut into the stock to provide a more diagonal angle for the trigger hand. Modern target style stocks have moved towards a fuller, more vertical grip, though built into the stock rather than made as a separate piece, and may be considered grip stocks. Anschütz stocks (C), for example, use a nearly vertical grip, and many thumbhole style stocks (D) are similar to full grips in shape.



Sliding or folding stocks are often seen on military-grade arms. A butt hook, which is an attachment to the butt of the gun
Gun
A gun is a muzzle or breech-loaded projectile-firing weapon. There are various definitions depending on the nation and branch of service. A "gun" may be distinguished from other firearms in being a crew-served weapon such as a howitzer or mortar, as opposed to a small arm like a rifle or pistol,...

 that is put under the shooter's arm to prevent the rifle from pivoting forward from the weight of the barrel
Gun barrel
A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....

 is sometimes used in competitive rifle shooting
Shooting
Shooting is the act or process of firing rifles, shotguns or other projectile weapons such as bows or crossbows. Even the firing of artillery, rockets and missiles can be called shooting. A person who specializes in shooting is a marksman...

. These stocks are also used on combat shotgun
Combat shotgun
A combat shotgun is a shotgun that is intended for use in an offensive role, typically by a military force. The earliest shotguns specifically designed for combat were the trench guns or trench shotguns issued in World War I...

s like the Franchi SPAS-12
Franchi SPAS-12
The SPAS-12 is a combat shotgun that was manufactured by the Italian firearms company Franchi S.p.A. from 1979 to 2000. The SPAS-12 is a dual-mode shotgun, meaning it can be calibrated to cycle either semi-automatically or through pump-action. The SPAS-12 has sold well to military and police users...

 to allow the stock to collapse when not in use.

The comb is another area of wide variation. Since the comb must support the shooter's cheek at a height suitable for use with the sights, high sights such as telescopic sight
Telescopic sight
A telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point...

s require higher combs. The Monte Carlo comb (B) is commonly found on stocks designed for use with scopes, and features an elevated comb to lift the cheek higher, while keeping the heel of the stock low. A cheekpiece (C) is a raised section on the side of the stock, which provides support for the shooter's cheek. There is some confusion between these terms, as the features are often combined, with the raised rollover cheekpiece (D) extending to the top of the stock to form a high Monte Carlo comb.

Fore-ends tend to vary both in thickness, from the splinter fore-ends common on British side-by-side shotguns to the wide, flat bottomed beavertail fore-ends found on benchrest shooting
Benchrest shooting
Benchrest shooting is a sport in which very accurate and precise rifles are shot at paper targets from a rest or bench from a sitting position. Benchrest shooters are notoriously detail-oriented and constantly trying to further the accuracy potential of the rifle through experimentation. Nearly...

 guns, and in length, from the short AK-47 style to the long Mannlicher stock that runs all the way to the muzzle. Most common on sporting firearms is the half-stock, which extends roughly half the length of the barrel.

Stock measurements


Stock measurement is especially important with shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

s, where the typical front-bead-only sight requires a consistent positioning of the shooter's eye over the center of the barrel for good accuracy. When having a stock custom built or bent to fit, there are a number of measurements that are important.
  • Length of pull, the length measured from the butt of the stock to the trigger
  • Drop at heel, the distance from the line of sight to the heel of the butt
  • Drop at comb, the distance from the line of sight to the comb
  • Cast off, the distance from the center of the butt to the center of the barrel, to the right side as seen from the rear
  • Cast on, the distance from the center of the butt to the center of the barrel, to the left side as seen from the rear
  • Pitch, the angle of the butt of the stock, determined by a line from heel to toe.

Accuracy considerations



In addition to ergonomic issues, the stock can also have a significant impact on the accuracy of the rifle. The key factors are:
  • A secure fit between the stock and action, so that the rifle does not shift under recoil
  • A stable material, that does not suffer from changes in shape with temperature, humidity, or other environmental conditions to a degree that could adversely impact accuracy

A well designed and well built wooden stock can provide the secure, stable base needed for an accurate rifle, but the properties of wood make it more difficult than more stable synthetic materials. Wood is still a top choice for aesthetic reasons, however, and solutions such as bedding
Rifle bedding
Rifle bedding is the process of filling gaps between the action and the stock of a rifle with an epoxy based material. The bedding creates a stable and precise fit for the contact surfaces...

 provide the stability of a synthetic with the aesthetics of wood.

Construction


Traditionally, stocks are made from wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

, generally a durable hardwood such as walnut
Walnut
Juglans is a plant genus of the family Juglandaceae, the seeds of which are known as walnuts. They are deciduous trees, 10–40 meters tall , with pinnate leaves 200–900 millimetres long , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts , but not the hickories...

. A growing option is the laminated wood stock, consisting of many thin layers of wood bonded together at high pressures with epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....

, resulting in a dense, stable composite.

Folding, collapsible, or removable stocks tend to be made from a mix of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 or alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

 for strength and locking mechanisms, and wood or plastics for shape. Stocks for bullpup
Bullpup
Bullpups are firearm configurations in which the action is located behind the trigger group and alongside the shooter's face, so there is no wasted space for the buttstock as in conventional designs. This permits a shorter firearm length for the same barrel length for improved maneuverability, and...

 rifles must take into account the dimensions of the rifle's action, as well as ergonomic issues such as ejection.

Wood stocks


While walnut is the favored gunstock wood, many other woods are used, including maple
Maple
Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

, myrtle, birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

, and mesquite
Mesquite
Mesquite is a leguminous plant of the Prosopis genus found in northern Mexico through the Sonoran Desert and Chihuahuan Deserts, and up into the Southwestern United States as far north as southern Kansas, west to the Colorado Desert in California,and east to the eastern fifth of Texas, where...

. In making stocks from solid wood, one must take into account the natural properties and variability of woods. The grain of the wood determines the strength, and the grain should flow through the wrist of the stock and out the toe; having the grain perpendicular to these areas weakens the stock considerably.

In addition to the type of wood, how it is treated can have a significant impact on its properties. Wood for gunstocks should be slowly dried, to prevent grain collapse and splitting, and also to preserve the natural color of the wood; custom stockmakers will buy blanks that have been dried two to three years and then dry it for several additional years before working it into a stock. Careful selection can yield distinctive and attractive features, such as crotch figure, feathering, fiddleback, and burl, which can significantly add to the desirability of a stock. While a basic, straight grained blank suitable for a utilitarian stock might sell for US$20, an exhibition grade blank with superb figure could price in the range of US$2000. Blanks for one piece stocks are more expensive than blanks for two piece stocks, due to the greater difficulty in finding the longer blanks with desirable figure. Two piece stocks are ideally made from a single blank, so that the wood in both parts shows similar color and figure.

Injection molded synthetic


While setup costs are high, once ready to produce, injection molding
Injection molding
Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Material is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the cavity...

 produces stocks for less than the cost of the cheapest wood stocks. Every stock is virtually identical in dimension, and requires no bedding, inletting, or finishing. The downsides are a lack of rigidity and thermal stability, which are side effects of the thermoplastic
Thermoplastic
Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...

 materials used for injection molding.

Hand-laid composite stocks


A hand-laid composite stock is composed out of materials such as fiberglass, kevlar, graphite cloth, or some combination, saturated in an appropriate binder, placed into a mold to set, or solidify. The resulting stock is stronger and more stable than an injection-molded stock. It can also be as little as half the weight of an injection-molded stock. Inletting and bedding can be accomplished by molding in as part of the manufacturing proceess, machining in the inletting after the stock is finished, molding directly to the action as a separate process, or molding a machined metal component in place during manufacture. Finish is provided by a layer of gel coat applied to the mold before the cloth is laid up.

Laminated wood


Laminated wood consists of two or more layers of wood, impregnated with glue and attached permanently to each other. The combination of the two pieces of wood, if laid out correctly, results in the separate pieces moderating the effects of changes in temperature and humidity. Modern laminates consist of 1/16 inch (1.6 mm) thick sheets of wood, usually birch, which are impregnated with epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....

, laid with alternating grain directions, and cured at high temperatures and pressures. The resulting composite material is far stronger than the original wood, free from internal defects, and nearly immune to warping from heat or moisture. Typically, each layer of the laminate is dyed before laminating, often with alternating colors, which provides a pattern similar to wood grain when cut into shape, and with bright, contrasting colors, the results can be very striking. The disadvantage of laminate stocks is density, with laminates weighing about 4 to 5 ounces (110 to 140 g) more than walnut for a typical stock.

While wood laminates have been available for many years on the custom market (and, in subdued form, in some military rifles), in 1987 Rutland Plywood, a maker of wood laminates, convinced Sturm, Ruger
Sturm, Ruger
Sturm, Ruger & Company, Incorporated is a Southport, Connecticut-based firearm manufacturing company, better known by the shortened name Ruger. Sturm, Ruger produces bolt-action, semi-automatic, full-automatic, and single-shot rifles, shotguns, semi-automatic pistols, and single- and double-action...

, Savage Arms
Savage Arms
The Savage Arms Company is a firearms manufacturing company based in Westfield, Massachusetts, with a division located in Canada. The company makes a variety of rimfire and centerfire rifles, as well as marketing the Stevens single-shot rifles and shotguns...

, and U.S. Repeating Arms Company
U.S. Repeating Arms Company
The U.S. Repeating Arms Company. Inc. is the current business name of the Winchester Repeating Arms Company, famous for making Winchester rifles....

 (Winchester) to display some laminate stocks on their rifles in a green, brown and black pattern (often called camo
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...

). The response was overwhelming, and that marked the beginning of laminated stocks on production rifles.

Metal


Some firearms (such as the PPS-43, MP-40, and the Zastava M70B) make use of metal stocks in order to have a strong, thin stock that can be folded away in order to make the weapon more compact. It should be noted that even a skeletal steel stock is often heavier than the equivalent wooden fixed stock.

Legal issues


In some jurisdictions, the nature of the stock may impact the legal status of the firearm. Examples of this are:
  • Adding a shoulder stock on a firearm with a barrel shorter than 16 inches (40.6 cm) makes it a short-barreled rifle under the US National Firearms Act
    National Firearms Act
    The National Firearms Act , 73rd Congress, Sess. 2, ch. 757, , enacted on June 26, 1934, currently codified as amended as , is an Act of Congress that, in general, imposes a statutory excise tax on the manufacture and transfer of certain firearms and mandates the registration of those firearms. The...

    .
  • Folding stocks or stocks with separate grips are banned features in some state and local legislation.