Forum Dictionary

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FORUM DICTIONARY  The Forum Dictionary has been compiled using various sources freely available. Every effort has been made to ensure that the entries are accurate and up to date. If you find an incorrect entry or wish to submit your own, please do not hesitate to contact one of the Moderators.

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

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A

Action

The mechanism of a gun by which it is loaded, locked, fired and unloaded.

 

Aim

The process of aligning the gun with the target, usually by means of the sights.

 

Aiming Mark

That part of the target which is used to align the sights onto the target. Usually, but not always the aiming mark is a black disk in the centre of the target sheet.

 

Aiming picture

The appearance of both sights and target when they are correctly aligned.

 

Airgun

A term applied to any rifle or pistol that uses some form of compressed gas as the propellant.

 

Air resistance

The slowing effect on a projectile in flight, due to friction with the atmosphere.

 

Ammunition

The name given to the 'fuel' used by all types of gun. It must be realised that 'bullet', 'round', 'cartridge', 'nature', 'pellet' and 'projectile' are all parts of the make-up of ammunition.

 

Aperture Sights

The standard type of sights used on air rifles and .22 rifles for target shooting. The sights consist of a rear unit with a small hole in it which is used to centralise the eye. A fore sight containing a ring, in the centre of which the (round) aiming mark is placed.

 

Artificial Target

Clay or card target used for shooting practice.

 

Automatic

A term used to describe a semi-automatic pistol. A semi automatic is a self-loading gun which fires one shot for each pull of the trigger. A full automatic is a gun which continues to fire once the trigger is pulled.

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B

Bag

Total number of birds or animals shot in one day/session.

 

Ball

Either a standard cylindrical bullet (see below) or literally a round ball which is often used in Black Powder guns, especially smoothbores.

 

Ballistic coefficient

A measure of a given projectile's ability to overcome air resistance in flight when compared to a standard projectile used to calculate ballistic tables. The BC will always be less than 1 and the higher the number the better. For example a BC of .39 is better than one of .142, especially as the range increases.

 

Ballistics

The study of what happens to a fired projectile. The study is divided into, internal, external and terminal ballistics. For target shooting purposes it is the first two which are important.

 

Barrel

That part of a gun along which the bullet or pellet(s) travel when fired, it is usually but not always circular in cross-section.

 

Barrel length

Normally this is the distance from the muzzle to the chamber and it includes the chamber itself. This measurement does not include accessories or barrel extensions like flash suppressors or muzzle brakes. The barrel length of a revolver is the distance from the muzzle to the breech end immediately in front of the cylinder, it does not include the cylinder itself.

 

Barrel Selector

Determines which barrel of a double barrel gun will fire first.

 

BB

Round ball Airgun projectile of .175 inch diameter, OR, A round shotgun cartridge projectile of .181 inch diameter.

 

BB Cap

Bulleted Breech Cap, an almost obsolete .22 rimfire cartridge, usually powered by the primer alone and firing a very light bullet. It is physically much shorter than a .22 short rimfire round.

 

Beater

A person who flushes wild game.

 

Bedding

The manner in which the barrel and action of a long arm are fitted to the stock: the point(s) of contact in fact between the two.

 

Belted Case

A rimless cartridge case with a raised integral belt around the case just ahead of the extractor groove to provide a positive headspace surface while retaining the extractor groove. This type of construction is usually used only on large capacity magnum rifle cartridges.

 

Bench Rest

A form of shooting done with the gun supported in some way, either partly or wholly, on a 'bench' rather than solely by the marksman, OR, a device for testing the accuracy of guns and ammunition.

 

Berdan

A centrefire primer system developed by Hiram Berdan (an American) in 1858. It is characterised by having multiple flash holes and an integral anvil in the case. Berdan cases are not as easy as Boxer cases to reload, due to the multiple, non central flash holes making removal of the fired primer more difficult.

 

Bigbore

Centrefire calibres larger than .22 rimfire. Generally taken as a synonym for Fullbore.

 

Bipod

A twin legged support for a rifle, usually fixed at the end of the stock away from the shooter.

 

Black Powder

Gunpowder used to operate muzzle loading guns.

 

Blank

A cartridge loaded without a bullet. On firing it produces the usual loud 'bang' but with little danger to life.

 

Blow-back

The method of operating low-powered semi-automatic guns. The bolt is literally 'blown' open by the cartridge when the gun is fired. It is normally used for .22 rimfire ammunition only.

 

Blueing

An oxidation (rusting) process normally applied to firearm metal parts. It is controlled by applying oil (usually heated) which mixes with the nitrates used in the process. The oil prevents further rusting by sealing the metal. This gives the metal a blue/black colour. It is also possible to "brown" or "black" guns by a similar process.

 

Boat Tail

The tapered rear end of some bullets, used to increase ballistic efficiency at long range by reducing atmospheric drag. So-called because in plan view the bullet outline resembles that of a boat.

 

Bolt

A steel rod-like assembly similar in design and operation to a normal door bolt, which moves back and forth in the action when operated by the shooter's hand. It seals the cartridge in the chamber during firing and extracts it afterwards, OR, In automatic and semi-automatic repeating guns, it loads the rounds from the magazine and unloads the fired cases, it may only have a passing resemblance to a door bolt and may not turn to lock.

 

Bolt Action

A type of gun, usually, but not always a rifle, which is loaded and unloaded by means of a bolt. It can be either a single shot, or a multi shot gun.

 

Bore

The interior diameter of the barrel of a firearm between the chamber and the muzzle, OR, The British word for the calibre of a shotgun.

 

Bore diameter

In rifled arms, the diameter formed by the top of the lands, in smooth bores, the diameter of the barrel just ahead of the chamber.

 

Bore line

An imaginary line projected from the muzzle of a gun along the centre of the bore.

 

Bottleneck Case

Cartridge case with a neck diameter smaller than its body diameter thus creating a shoulder and giving the case the appearance of a wine bottle in profile.

 

Boxer

A centrefire primer system developed by Edward Boxer in 1858. It is characterised by having one central flash hole and the anvil as an integral part of the primer. Very easy to reload and used by the American armed forces and most home reloaders in the UK.

 

Box-Lock

A type of gun action, often recognisable by its squared appearance.

 

Brass

A term used to mean empty, reloadable cartridge cases.

 

Breech

The end part of the barrel nearest the shooter with the chamber into which the cartridge or projectile is loaded.

 

Breech loader

A firearm loaded through the breech end. Note that this does not automatically imply a gun firing metallic cartridge cases: see muzzle loader below.

 

Brisance

In addition to strength, explosives display a second characteristic, which is their shattering effect or brisance, which is distinguished from their total work capacity. This characteristic is of practical importance in determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, and the like. The rapidity with which an explosive reaches its peak pressure is a measure of its brisance. This term is often misused to indicate a primer's ability to set-off the main charge in a metallic cartridge.

 

Broken Gun

In a hinge type gun, where the barrels are dropped open and clear of the action, exposing the chambers to view.

 

Browning

Referring to the act of shooting in the midst of a covey or flock of birds without aiming at a particular bird, also known as blazing or creaming. -or- A well known gun manufacturer.

 

Bull

The centre of a target.

 

Bull Barrel

A firearm built with an extra thick-walled barrel that adds weight to the gun and especially to the muzzle end. It thus reduces recoil and minimises the effects caused by heating when firing rapidly.

 

Bullseye

The centre of a target, OR, A type of fast burning smokeless powder made by Hercules and particularly suited to cartridges intended to be shot by short barrelled guns.

 

Bullet

The name given to the single, usually cylindrical projectile that comes out of the barrel of a gun. If there is more than one projectile, then usually the term used is 'pellet', as in a shotgun cartridge.

 

Bullet Catcher

The part of the butts which actually stops and retains the fired bullet.

 

Bullet Mould

A device of either steel or aluminium used to cast bullets for home reloading. The molten material (usually lead, or an alloy of lead) is poured into the mould and when set, the bullet can be removed and loaded to make a complete cartridge.

 

Bullet path

The track or path taken by a bullet in flight. It is described by the position of the bullet as being above or below the line of sight at any given distance. Also known as the bullet trajectory.

 

Bullet puller

A device used to 'pull' a bullet from its cartridge case. Normally, either a collet is clamped round the bullet and it is literally pulled from the case, or an inertia hammer is used, whereby the case is held and the bullet 'pulled' by its own inertia, when the tool is struck against a hard object.

 

Burning rate

The relative speed at which a propellant powder burns in comparison to other powders in a controlled combustion chamber.

 

Butt

The rear end of a rifle or shotgun stock. In a handgun, the bottom part of the grip.

 

Butt Plate

The plate, usually of some rubber, or plastic compound that cushions the shooters shoulder from recoil when a long-arm is fired. It is fitted onto the end of the stock.

 

Butts

The name given to that part of the range which contains the target frames and the bullet catcher which traps and safely contains the fired projectiles.

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C

Calibre

The diameter of a projectile, or the bore of a firearm. In rifled arms this measurement is from top of land to top of land across the bore diameter. This is not always quite what it seems, for example a .38 and a .357 calibre bullet are exactly the same diameter (the same bullet in fact). Quite often the name given to a particular gun, such as a .44 magnum, is a label or a name, not an actual measurement of calibre.

 

Cannelure

The circumferential groove or indentation in a cartridge case and / or bullet used to hold the projectile in place and prevent its rearward movement on loading, or whilst in the magazine during recoil.

 

Cant

The angle of lean from the vertical that the firearm has whilst being held by the shooter.

 

Cap

An explosive device fitted over the nipple of a percussion Black Powder gun in order to initiate ignition of the main charge and fire the bullet.

 

Capping off

The process of firing a cap on its own before attempting to load a percussion fired Black Powder gun, in order to clear any oil or other residue from the nipple and chamber.

 

Carbine

Usually taken to be a shortened version of a long arm, held in two hands and firing a pistol calibre cartridge.

 

Carbon Dioxide

Used as a propellant for 'air' guns. It is stored on the gun in liquid form under pressure and typically will give around 180 shots per fill from a purpose designed reservoir.

 

Cartridge

Metal (rifle) or plastic (shotgun) casing containing propellant charge and projectile

 

Cartridge Case

The cylindrical case, usually of brass that holds the primer, main charge and bullet of a complete round of ammunition. The brass case is the most expensive part of a cartridge and in the instance of centrefire cartridges they can be reloaded.

 

Cast

The type of bullet produced by a lead melting process, OR, The process of making bullets for reloading by melting lead, or an alloy of lead. These bullets are normally not jacketed and so are only suitable for relatively low velocities. The process is quite suitable for home production.

 

Centrefire

A cartridge ignited by a primer located in the centre of the case head. The system is suitable for reloading the cartridge case and is suited to high pressure ammunition. See also the entries for Berdan and Boxer.

 

Chain Firing

See Cross Ignition.

 

Chamber

The part of a firearm containing the cartridge (or separate powder and ball) at the moment of firing it, normally at the opposite end of the barrel to the muzzle, OR, The action of loading a round of ammunition into the gun.

 

Charge

In the case of nitro powder and Black Powder, the amount, by weight, of the powder in a cartridge or load, OR, In the case of Pyrodex, the amount, by volume, of the powder used, OR, To fill a magazine with cartridges.

 

Cheek Piece

A lateral projection from the comb of the stock. Provides additional support and contact to the shooter's cheek when the rifle is shouldered in the firing position. It is used to assist positioning the aiming eye correctly behind the sights.

 

Choke

The restriction at the muzzle of a shotgun used to control the dispersion of the shot.

 

Chronograph

A device to measure the velocity of projectiles fired from a gun.

 

Clay pigeon/clay

Disc of pitch and chalk thrown into the air to practice shotgun shooting

 

Cleaning rod

A rod, usually of plastic coated metal, longer than the barrel to be cleaned and often fitted with a ball-bearing handle. This rod takes a variety of cloths, or other attachments and pulls and pushes them through the barrel in order to clean it of any deposits.

 

Click

The name given to the smallest adjustment of a sight, it is an onomatopoeic word.

 

Clip

The name given to a metallic device to hold a group of cartridges together prior to loading them into the gun's magazine, OR, An incorrect word used to describe a magazine and / or its contents.

 

Close season

Dates during which a quarry species is protected by law and may not be shot

 

Cock

To set the action into position for firing. On most muzzle loading firearms, the action has an intermediate position called half-cock.

 

Comb

The upper part of the stock where the shooter's cheek rests during aiming.

 

Compensator

A muzzle brake, designed to reduce the felt effects of recoil by redirecting the escaping gases and to limit the muzzle jump on firing so as to assist rapid subsequent shots.

 

Cordite

The trade name of one of the earliest smokeless propellants made in Britain, so called because of its long, cord-like appearance. It is not used today for smallarms, mainly because its high burning temperature leads to premature bore erosion.

 

Crimp

The inward folding of a cartridge case used to retain the projectile (or shot charge in a shotgun). It can be either tapered, or rolled.

 

Cross-ignition

The term used to describe the dangerous possibility with a Black Powder revolver of multiple discharges when the primary cylinder is fired. This is as a result of the other cylinders being set off as a result of sparks from the primary cylinder igniting them when they are not lined up with the barrel. The original precaution was to put grease over the open ends of all cylinders as a sealant; the modern idea is to use impregnated felt wads as this is considerably less messy.

 

Crown

The bevelled, countersunk, or rounded muzzle surface of a barrel, done thus to protect the point of exit from accidental damage.

 

Cull

To kill selectively (especially old and weak) individuals, to maintain the health of the herd

 

C.U.P. ... Copper Units of Pressure

One of the standard methods of estimating the pressure inside a gun when it is being fired. Of great importance for safe reloading, as cartridge cases are quoted by their manufacturers as having a particular maximum c.u.p. which must not be exceeded.

 

Cylinder

That part of a revolving firearm which holds the ammunition in individual chambers. The cylinder then rotates as the gun is used to present each round in turn to the barrel for firing.

 

Cylinder Gap

The gap between the front of the cylinder and the rear of the barrel of a revolver. This can be as small as 1/1000 of an inch in a high quality gun, but is usually nearer 1/100 of an inch. Some gas escapes as a result of the gap and bullet velocity is reduced, typically by about 5%.

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D

Damascus

An early method of making barrels out of welding together two or more rods of twisted iron and rolling them into a ribbon. This ribbon was then wrapped round a mandrel and hammered so that the edges became fused together. The result was a pretty patterned barrel of considerable aesthetic appeal and relatively little strength, for Black Powder use only and not to be used with nitro powder.

 

Decoy

A dummy designed to lure birds, especially woodpigeon, within shooting range. Also refers to a pond used for trapping ducks.

 

Deer Stalker

A person who approaches deer without being noticed in order to shoot selective animals

 

Density

In the context of reloading this means, 'sectional density', or SD, which is the mass of a bullet in proportion to its cross-section. For simplicity the SD is usually calculated by dividing the weight (in grains) by the square of the diameter. As an example take a 150 grain bullet from a .308 Winchester: divide 150 by the square of .308 (.0949) to get 1581.2 and divide again by 7000 (the number of grains in a pound weight) to get .226 which is the SD.

 

Die

A tool used in reloading metallic cartridge cases to resize the case to the specified dimensions, or a tool used to de-prime fired cases, or a tool used to seat bullets in cases, or a tool used to load powder into cases prior to seating the bullet.

 

Dioptre

Refractive power of a lens. A lens having a focal length of one metre is said to have a power of one dioptre, a lens of 20 centimetre focal length has a power of +5 dioptres, one of 5 metres focal length has a power of -5 dioptres.

 

Disconnector

Mechanical device in a semi-automatic gun that is designed to prevent the firing of more than one shot from one pull of the trigger.

 

Dominant Eye (and Hand)

The stronger, or 'master' eye and hand. The dominant eye is the one through which a person would usually view an object when using a telescope. The dominant hand is what the shooter would describe himself as being: for example, 'right-handed'. This causes the shooter a problem when the dominant eye is on the other side of the body to the dominant hand. In about 15% of the population the dominant hand and eye are on opposite sides. This is much less of a problem for pistol shooters than anyone using a long arm.

 

Double Action

The type of firearm action whereby one pull of the trigger performs the two separate functions of, cocking the gun and firing the gun.

 

Double-base

Propellant powder in which nitro-cellulose is supplemented by nitro-glycerine.

 

Drag

See air resistance above.

 

Drift

The lateral movement of a projectile due to rotation in flight through the atmosphere. If the gun has rifling with a left hand twist, the movement will be to left and vice versa, OR, The lateral movement of a projectile due to wind.

 

Driven (shoot)

Form of sport in which game birds are flushed over the standing Guns

 

Drop

The distance that a projectile falls at any given distance from the gun, OR, The distance that the centre of the butt of a long-arm is below the centre line of the barrel. Both distances are measured in inches using the Imperial system.

 

Dry Fire

Firing of an unloaded firearm to practice handling and shooting techniques. This can damage some types of actions, particularly rimfire unless a Dummy Cartridge, or Snap Cap is loaded to absorb the shock to the firing pin.

 

Dummy Cartridge

Sometimes called, 'Drill rounds', these are cartridges assembled without either propellant or primer and use to test the functioning of guns and magazines without any danger of an accidental discharge. These special cartridges have to be indelibly marked to avoid fatal confusion.

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E

Ejector

The mechanism which expels the cartridge or case from the breech of the gun.

 

Elevation

Vertical sight movement so as to raise (or lower) the point of impact on the target.

 

Energy

The force of a projectile at any given distance. The energy in ft/lbs. (foot-pounds) can be calculated from the weight of the projectile and its velocity. For example take a 150 grain bullet moving at 2800 fps (feet per second): Energy = (bullet weight x velocity squared) divided by 450,400 = 2611 ft/lbs. This formula is based on: k=?mv2 and includes allowing for converting bullet weight from grains to pounds and assumes that the acceleration due to gravity is 32.174 fps2.

 

Eye Piece

The lens of a telescopic sight nearest the shooters eye.

 

Eye Relief

The distance that the shooters eye is positioned behind the ocular (eye) lens of a telescopic sight in order to obtain the best view of the target and to avoid a black-eye on firing. Somewhere between 2 to 4 inches is the usual distance.

 

Explosive

Explosives are classified as low or high according to the detonating velocity or speed at which they change from being a solid or liquid to gas and other pertinent characteristics such as their shattering effect (or brisance). An arbitrary figure of 3300 fps is used to distinguish between burning / deflagration (low explosive) and detonation (high explosive). A propellant is said to burn at less than the speed of sound (approximately 1100 fps). Within the UK the possession and use of any explosive is subject to having the necessary licence.

 

Extractor

The device which extracts, or removes the cartridge or cartridge case from the chamber of the gun.

 

Eye relief

The distance, usually about 4 inches, between the shooter's eye and the rearmost part of the sights. This distance is important both for good vision of the target and to prevent injury when shooting a gun with significant recoil. In the case of Telescopic Sights there are special models available for use with hand guns which have extended eye relief, so as to allow their use at about 18 inches from the eye.

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F

Falling Block Action

A single-shot firearm action in which a solid metal breechblock slides vertically in grooves cut into the breech of the rifle and actuated by a lever.

 

When in the top position, it is locked and resists the force of recoil while sealing the chamber. In the lower position, it leaves the chamber open to be loaded by a cartridge from the rear. After loading, the lever returns the block to the top position to lock the breech in place to seal the chamber.

 

Felt recoil

The way that a shooter actually feels the recoil, or 'kick' of a gun when it is fired. In general, guns firing ammunition with a nitro powder will have a sharper, more jarring recoil that those firing Black Powder. Guns with some form of automatic, or semi-automatic loading mechanism feel less harsh than those without, due to the operation of the gun 'spreading' the recoil out over a longer time period.

 

Fg, FFg, FFFg, FFFFg

Grades of size of Black Powder particles, from coarsest to finest. FFFFg is mainly used as a priming powder for flintlocks, wheel locks and matchlocks. Also see 'Swiss' below.

 

Firearm

Any gun which uses the combustion of a propellant or an explosive to discharge a projectile.

 

Firearms Certificate (FAC)

The necessary permit to hold any firearm or ammunition in the UK, it lasts for 5 years before renewal, a simpler form of licence is required for shotguns.

 

Fireform

The process of changing the shape (and volume) of a cartridge case by firing with (normally) a light load in the gun in which it is to be used. This is a means of improving accuracy and functioning by matching the case to the exact size of the chamber of a particular gun.

 

Firing Pin

The part of a gun's action which actually strikes the primer so as to set it off and initiate firing the cartridge's main charge of propellant.

 

Firing Point

The physical position from which a shot is taken.

 

Fixed Sights

Non-adjustable sights, not used for serious target work.

 

Flash Hole

The small diameter hole through which the 'flash' from the priming charge of a muzzle loading gun travels to ignite the main charge, OR, The small diameter hole or holes through which the flame from the primer of a centrefire cartridge passes to ignite the main charge in the cartridge case.

 

Flashing Pans

The action before the commencement of shooting, of firing off a priming charge of powder from the pan of a matchlock, wheel lock or flintlock muzzle loading gun in order to clear any oil or other residue from the flash hole and chamber, before loading the main charge: see Capping off above.

 

Flash in the pan

What happens when the priming powder in the pan of a matchlock, wheel lock or flintlock gun goes off without igniting the main charge, OR, A short-lived enterprise of some sort.

 

Flashover

See Cross Ignition.

 

Flight

Movement of pigeon or wildfowl at dawn and dusk between resting and feeding areas

 

Flightline

Paths in the sky routinely taken by birds to move between roosting and feeding areas

 

Flight pond

Area of water into which wildfowl drop to feed and roost

 

Flinch Flinching

The involuntary physical reaction by the shooter to the firing of the gun. This movement spoils the accuracy of the shot and can be a difficult problem to cure.

 

Flintlock

A muzzle loading firearm with its powder charge ignited by a flint striking a metal surface (the frizzen) to produce sparks which ignite fine priming powder, which in turn sets off the main charge.

 

Flush

To rouse game

 

Follow-through

Staying in the same position after pulling the trigger, or continuing the swing when firing at a moving target. This is done in order to assist in, 'calling the shot'.

 

Foot-pound

The energy required to lift one pound through a distance of one foot.

 

Forcing Cone

The tapered section of a shotgun or revolver barrel where the pellets or bullet is guided into the bore.

 

Forearm

The part of the stock that lies under the barrel.

 

Fouling

The deposits that build up in the barrel of a gun after it is fired. Fouling can either be soft and harmless carbon residue, or more persistent lead or copper, both of which are detrimental to accuracy.

 

Fouling Shot

The process of firing a shot off before starting trying to shoot accurately, so as to remove any oil from the barrel and to coat the bore with a layer of powder residue. This process is most important for muzzle loading guns in order to obtain consistent accuracy.

 

FPS

Feet per second, the standard measure of projectile velocity in the Imperial measurement system.

 

Free Bore

The unrifled portion of the bore, if any, in front of the chamber, it can be up to about a half the length of the barrel. Not much used these days and normally only for low-powered cartridges such as the .22 rimfire.

 

Frizzen

The upright steel plate in a flintlock gun which is struck by the flint in order to produce the sparks for igniting the priming powder. Note: the sparks come from the steel NOT the flint!

 

Ft/lb

Foot-pound, the standard unit of energy in the Imperial measurement system, used as a measure of the energy contained in a bullet in flight.

 

Full Bore

Generally taken to mean centrefire calibres, especially those of .22 and greater.

 

Full Choke

The tightest constricting or narrowing of the bore, producing the greatest effective range.

 

Full-Cock

The action of setting the action (see above) into the ready to fire position. See half-cock and cock.

 

Full Metal Jacket

A jacket, usually of copper completely covering a bullet, so as to leave no lead exposed. Much used for military ammunition as it helps to comply with the Geneva Convention on Land Warfare, which specifies that expanding ammunition must not be used against human targets. It also allows the bullet to be driven much faster than a plain lead projectile.

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G

Gain twist

A system of rifling with the pitch increasing towards the muzzle.

 

Game

Selected wild animals and birds defined in law and hunted for sport and food

 

Gamekeeper

Person who rears game birds for release into the wild and manages their habitat

 

Gas Cutting

What happens when using high pressure cartridges in a revolver and the gasses literally cut the metal of the top strap of the frame when they escape through the cylinder / barrel gap.

 

Gauge

The term used to describe the interior diameter of the bore. The smaller the gauge number, the larger the bore size. Modern shotguns are available in 10, 12, 16, 20, and 28 gauge. An exception is the .410 bore shotgun, which is actually a 67 gauge.

 

Ghillie

A hunting guide, particularly in Scotland, who accompanies shooters or fishermen

 

Grain

A unit of weight used to measure powder charges and bullets. By definition it is 1/437.5 of an ounce avoirdupois and therefore there are 7000 grains to the pound, OR, The natural pattern of wood.

 

Greenhill’s Formula

An empirical formula that relates bullet weight and length to rifling twist. One must bear in mind that the formula assumes cylindrical pure lead bullets and doesn't work as well for small calibres as it does for large ones. Twist in inches (T) = [150/(L/D)]xD where L = bullet length in inches and D = bullet diameter in inches. It is best regarded as a starting point when determining rifling twist rates and not as an exact measure. See, Rate-Of-Twist below.

 

Grip

The narrow portion of the stock held with the trigger hand.

 

Groove

The sunken part of rifling.

 

Groove diameter

The distance across the bore of a rifled barrel from the bottom of one groove to the bottom of the one opposite, this is easily measured by means of a lead slug. In the case of a barrel with an odd number of grooves this is measured by driving a soft lead slug into the barrel and then measuring the slug's diameter over a land-to-groove cross section and then subtracting the bore diameter. The next step is to double this figure and add it to the bore diameter to get the groove diameter.

 

Group

The pattern of shots on a target.

 

Group Size

It is the distance between the centres of the two farthest apart shots in a group. The easiest way to measure this, is to measure from the outside edge of one bullet hole to the inside edge of the one farthest away. Another method is to measure the distance from outside edge to outside edge of the farthest apart holes and then subtract the bullet hole diameter.

 

Gun

Another word for a shooter

 

Guncotton

Nitro-cellulose, a form of smokeless propellant.

 

Gundog

Specially bred and trained dog for locating, flushing and retrieving game

 

Gunpowder

An explosive made up of 70% saltpetre, 15% sulphur and 10% charcoal. It has been used as both an explosive for blasting and mining operations as well as to fire projectiles from firearms. Also known as, Black Powder: see above

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H

Half-Cock

The safety position for a matchlock, wheel lock, flintlock or percussion gun. The hammer is moved to a halfway position from which it cannot be released by the trigger and the gun can then be carried loaded in safety.

 

Hammer

The part of the action which drives the firing pin to strike the primer in a cartridge gun, OR, The part of the action which carries the flint for a Flintlock gun, OR, The part of the action which strikes the cap in a Percussion gun: see Serpent below for Matchlock guns.

 

Handload(ing)

The practice of loading and reloading centrefire cartridges to either save money and / or produce specific cartridge characteristics; for example low velocity, minimum recoil rounds for rapid-fire target shooting. This is most easily done using Boxer primed centrefire cases: see Boxer above.

 

Hang fire

A term applied to an excessive delay in ignition of the main charge after the primer has fired, this is mainly a problem for Black Powder muzzle loaders and especially Matchlocks.

 

Hanging

To suspend meat so that the flavour matures

 

Head (of game)

Number shot

 

Headspace

This is the distance from the breech face to that part of the chamber which stops the forward movement of the cartridge case. Different cartridge designs obtain their headspace in different ways. A rimmed case, such as a .22 rimfire uses the case rim to position the cartridge within the chamber, whilst a rimless cartridge, like the 9 mm Parabellum uses the rim of the case mouth, seating on an annulus in the chamber (this means that 9 mm cases must be both of exact length and not use a rolled crimp to hold the bullet in place).

 

Headstamp

The manufacturers marks stamped into the primer end of a metallic cartridge case giving various details of its construction, such as calibre, maker, load, date of manufacture, etc. There is no universal standard for this information and its value and content can vary widely.

 

Hide

Place of concealment blending into the natural environment

 

Hinge

A type of action in which a hinge mechanism separates the barrel from the standing breech block, providing access to the chamber.

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I

Inertia Firing Pin

A firing pin which is shorter than the guide in which it travels to strike the primer. It is propelled sufficiently quickly from its resting position to cover the distance from the hammer to the cartridge primer and then to detonate the primer, due simply to its own inertia.

 

Inertia puller

See bullet puller.

 

Inter-tidal

Area covered by water only at high tide.

 

Improved Cylinder

Less constricted than a modified or full choke - a good all around choke for sporting clays.

 

Iron Sights

See Metallic sights.

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J

Jacket

A covering over the lead core of a bullet. Usually this cover is made of copper and can be either complete, or partial. If partial, it can leave either the nose or the tail of the bullet exposed. An exposed nose is much used in hunting, as it allows the bullet to expand and transfer more of its energy to the game being shot. All jackets allow the bullet to be fired with greater velocity than plain lead could withstand.

 

Journee's Formula

The empirical formula used to calculate safe distances for shotgun pellets. It says that the maximum range in yards for a round pellet is 2200 times its diameter in inches.

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K

 

No entries for K.

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L
Lamping
Night shooting of pests and predators using a powerful spotlamp

Land
The raised portion of rifling.

Lapping
The process of repeatedly passing a lead 'slug' (usually a wadcutter bullet mounted on a cleaning rod) through the bore of a gun barrel in order to lap, or polish it. The polishing is assisted by means of dipping the slug in a mild metal polish, such as Brasso. This method is used to remove rough spots from the bore which can give rise to leading: see Leading below.

Leading
The deposition of lead in the bore of a gun due to the passage of lead projectiles (pronounced: "ledding"). Often caused by firing the bullets at too great a velocity, or by a slight roughness in the barrel, stripping a sliver of metal off as they pass.

Leade
The short unrifled section of the bore, if any, in front of the chamber, into which the bullet's nose is introduced (pronounced: "leed").

 

L.O.P....length of pull

Measurement from the end of stock to the trigger

Let-off
A somewhat vague term used to describe the release of the sear when the trigger is pulled to fire the gun. A 'crisp' let-off denotes a sudden release, like the click of a light switch, a 'rollover' let-off denotes a rather more vague firing point.

Load
To place a round of ammunition in a firearm chamber or magazine, OR, A specific type or composition of ammunition.

Lock
The firing mechanism of a muzzle loading firearm.

Lock, Stock and Barrel
The three main parts of a muzzle loading gun.

Lock time
The time taken from the release of the sear by the trigger to the moment the primer is struck, usually very short, less than 2 milliseconds being the aim.

Long-arm
Any gun held in two hands with a butt piece held against the shoulder.

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M

Machine Rest

A device for securely holding a gun in a consistent position so as to allow accuracy testing of gun and ammunition: see Bench Rest above.

 

Magazine

A device for holding ammunition ready for loading into the chamber of a repeating firearm, OR, A storage room for ammunition and, or explosives.

 

Magnum

A loose term used to signify a cartridge, either rimfire or centrefire of any size, for either rifle or pistol, which is loaded to higher than normal pressures, OR, A term used to describe firearms which are designed to fire magnum ammunition e.g. a Smith & Wesson model 29 .44 Magnum revolver.

 

Martini Rifle

A type of falling block action used in single shot guns. In the case of BSA .22 rimfire rifles the block is hinged at the rear. Viewed from the side with the breech open these guns bear a passing resemblance to Winchester under lever repeating centre fire rifles.

 

Match

A string soaked in nitrate so as to burn slowly and steadily without going out in wind, used to fire a Matchlock gun.

 

Matchlock

A muzzle loading firearm which is fired by means of a slowly burning match being applied to a flash hole by means of the trigger.

 

Mean Point of Impact

The mathematical centre of a group of shot holes on the target.

 

Metallic Sights

A somewhat loose term used to describe non-optical sights, especially open sights as fitted to handguns. Also known as, Iron sights.

 

Metplat

The diameter of the tip of a projectile. This is a somewhat difficult term to define exactly, but is usually taken to mean that part of the projectile after the dramatic change in radius as the tip is approached. In a full wadcutter bullet, the metplat and the calibre are one and the same diameter.

 

Minute of Angle (MOA)

The radial distance represented by 1/60 of a degree (there being 360 degrees in the circumference of a circle). The MOA is used in target shooting as a handy reference of accuracy and for sight adjustment. At a range of 100 yards 1 MOA represents a distance of 1.0472 inches (or approximately 1 inch). Sights are normally calibrated in fractions of a minute, a typical .22 target rifle with aperture sights will have 1/8 minute adjustments i.e. at 100 yards range, 1 click (see above) of the sight will move the point of impact 1/8 inch. General purpose telescopic sights normally have 1/4 minute adjustments.

 

Minie

A cylindrical shaped bullet used in muzzle-loaders. It has a pointed tip and a hollow base which spreads to give a good seal to the barrel in a similar manner to a pellet in an airgun when it is fired.

 

Monte Carlo Stock

A stock with a raised comb which provides elevated eye alignment when using a telescopic sight, which stands higher above the bore line than metallic sights.

 

Modified Choke

Moderate constriction or narrowing of the bore.

 

Musket

The name of a shoulder fired muzzle loading (and usually) smoothbore gun held in both hands.

 

Muzzle

The end of the barrel from which the projectile exits.

 

Muzzle blast

The blast, or shockwave felt by a shooter and observers when the bullet exits from the barrel.

 

Muzzle Brake

A device consisting of various vents either attached to, or integral with the end of the barrel which is designed to reduce the amount of felt recoil and muzzle jump. See compensator above.

 

Muzzle Crown

The process whereby the muzzle is rebated, or 'crowned' so as to provide some measure of protection from accidental damage to the bore of the barrel.

 

Muzzle energy

The energy, often measured in Foot-Pounds (ft/lb) that a projectile contains when it leaves the barrel of a gun.

 

Muzzle Flash

The flash, caused by unburned powder burning-up in free air after the bullet has left the barrel.

 

Muzzle jump

The vertical movement of the muzzle on firing the gun caused by the centre of the barrel being higher than the centre of support for the gun.

 

Muzzle Loader

Any gun which is loaded from the muzzle end, usually by means of a separate powder charge, with the bullet seated afterwards. Muzzle loaders can be, Matchlocks, Wheel Locks, Flintlocks, or Percussion fired. See Breech loader, above.

 

Muzzle velocity

The velocity of a projectile as it leaves the barrel of a gun, normally this is the maximum velocity reached (some military ammunition can be fitted with a secondary charge which can be fired later on to act as a booster).

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N

Nature

What the British army calls bullets, pellets, rockets and shells. See also the entry for, projectile.

 

Nipple

A drilled cone shaped part of a Black Powder gun, fitted at the end of the barrel, or chamber at the closed end and used to hold the percussion cap(s) needed to fire the main charge(s).

 

Nitro

Short for Nitro-cellulose, the standard form of smokeless propellant used today for cartridge guns of all types, OR, A term used to describe both the propellant nitro-cellulose and the guns themselves that have been made to use it.

 

Nitro-cellulose

Otherwise called guncotton. This is the basis of all modern smokeless propellants, it is made by dissolving cotton in nitric acid (do not try this at home).

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O

Object lens

The lens of a telescopic sight (or any optical device) nearest the object being viewed.

 

Obturation

The expansion of a cartridge case on firing to seal off the chamber and prevent gases from escaping.

 

Ogive

The curved portion of a projectile between the cylindrical radius and the metplat (diameter of the tip of the projectile).

 

Open season

Dates during which quarry species may be taken legally, also known as the shooting season

 

Open Sights

See metallic sights.

 

Over-and-under

Shotgun in which one barrel is on top of the other

 

Over-travel

The amount of rearward travel of the trigger after the release of the sear.

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P

Pan

That part of a matchlock, wheel lock or flintlock muzzle loading gun that holds the priming powder next to the flash hole so that the main charge can be ignited by it.

 

Parallax

The apparent shift in position of a viewed object attributable to the difference between two separate and distinct points of view. A major problem for users of telescopic sights without parallax adjustment, as these sights will only be free of error at one distance, usually 100 yards. Note that this is not the same thing as focussing and if a telescopic sight does not have an adjuster ring near the object lens, then almost certainly it does not have parallax adjustment. This means that apart from the one distance it is parallax free (usually 100 yards) it will be of little value for accurate target shooting purposes, no matter with what gun or ammunition it is used.

 

Patch

A small piece of leather or cloth that is greased and placed around a bullet before ramming it down the barrel of a muzzle-loader so as to hold it firmly in place and prevent it rolling out, OR, A piece of cloth drawn through the bore of a firearm to clean it.

 

Paunching

To pierce or rip the belly of; to eviscerate; to disembowel

 

Pellet

Either an airgun projectile, usually of lead, or a component of a shotgun cartridge which is fired out of the gun. Normally shotgun pellets are round balls of lead, or often these days, of steel.

 

Pelt

The skin of an animal with the fur or hair still on it, OR, A stripped animal skin ready for tanning.

 

Percussion

The name given to firing a gun by means of a percussion cap placed over the flash hole (called a 'nipple' on a percussion gun). Percussion guns are normally muzzle loaders and can be either single shot, or multi shot.

 

Picker-up

Person who retrieves dead and wounded game with the aid of gundogs

 

Pistol

A relatively short gun, usually under 24 inches long and held in one or both hands. Typically it will fire a reduced load cartridge compared to a rifle and normally in modern construction the barrel will be rifled to improve accuracy. See also the entries for Automatic and Revolver.

 

Plinking

An American term for casual, non-precision shooting, usually aimed at informal targets such as tin cans etc.

 

POA Point of Aim

The point at which you aim.

 

POI Point of Impact

The point at which the projectile impacts the chosen target.

 

Primer

An explosive compound fitted either all around the rim of a rimfire cartridge case, or in a centrally mounted cap (usually replaceable) for centre fire cartridges. It is used to set off the main charge, OR, The small charge of fine grained Black Powder used to ignite the main charge of a Matchlock, Wheel Lock or Flintlock gun.

 

Progressive

Name given to a type of reloading press whereby one pull of the operating lever competes one stage of the process and allows the press to be moved to the next stage.

 

Projectile

The name given to any item coming out of the barrel of any type of gun when it is fired.

 

Propellant

Any substance which can be used to operate a gun by burning in a controlled manner. In the UK propellants are not subject to the laws governing explosives and so can be freely bought by anyone over the age of 16 without a licence. Propellants are substances that support the spread of combustion at speeds below that of sound (approximately 1100 fps). They cannot be sent through the post within the UK.

 

Proving safe

The action of demonstrating that a gun is not loaded.

 

Pump Action

A type of action that loads and ejects shells by pumping the forearm of the stock back and forth.

 

Pyrodex

A Black Powder substitute: in the UK it is classed as a propellant and is thus free of licensing restrictions. It is corrosive to steel and guns have to be cleaned thoroughly after use.

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Q

 

No entries for Q.

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R

Ramrod

A rod of non ferrous construction used to 'ram' the ball (or bullet) down the barrel of a muzzle loading gun so as to seat it firmly on the charge of Black Powder. It must be made of a material which cannot strike sparks off the steel of the barrel. The ramrod can also be used to determine if a muzzle loading gun is actually loaded, by marking it so that one can tell when it reaches the end of the chamber and thus indicates that there is no charge present.

 

Range

The distance from the firing point to the target, OR, The location, either indoors or outdoors at which shooting takes place.

 

Receiver

The part of a breech loading firearm comprising of the chamber end of the barrel with the loading / unloading port.

 

Recoil

The rearward movement of a gun when fired. Note that it is in general more comfortable to fire a gun with heavy recoil from the standing, rather than the prone position. See also: felt recoil.

 

Refuge

A safe haven for wildlife where human activity is restricted

 

Reloading

The practice of reloading brass cartridge cases with primer, propellant and bullet so as to use them again. With light target loads straight-walled brass cartridge cases can be reloaded 20+ times. Note that other materials than brass have been used for cases, but brass is the only material to date which has demonstrated sufficient flexibility and elasticity to allow successful reloading of high pressure ammunition.

 

Reticule

The aiming device built into a telescopic sight, usually in the form of cross-hairs for target shooting purposes. There are many different forms of reticule for sporting use.

 

Rifling

Spiral grooving in the bore of a firearm that is used to spin-stabilise the projectile and thus improve its accuracy after leaving the barrel. Rifling can be either clock, or anti-clockwise in direction and can have either an even, or an odd number of grooves. Pistols can and usually do have rifled barrels, the system is not unique to 'rifles'.

 

Rimfire

A system of priming a cartridge case where the primer is held in the rim of the case and is set off by the cartridge case rim being struck and crushed. The cases cannot be reloaded and the system is only suitable for low pressure ammunition such as the .22 commonly used for target shooting.

 

Rough Shooting

Form of sport which is not pre-planned. See Walked up

 

Round

A complete item of ammunition with all components present to allow the firing of one shot. It can take several forms: for modern metallic ammunition it consists of a cartridge case with fitted primer, main charge and projectile(s) all assembled together, that is all the components together required to fire one shot, OR, for muzzle loading guns it refers to all the required components either in loose, or part assembled form to fire one shot (see this glossary for description of individual items).

 

Round nose

A bullet with a rounded head such as used in most .22 rimfire target cartridges. These bullets need the use of a scoring gauge on the target in order to determine the true value of the shot, due to the way that the hole closes up after they have passed through the paper.

 

Rut Rutting

An annually recurring condition or period of sexual excitement and reproductive activity in male deer, OR, A condition or period of mammalian sexual activity, such as estrus.

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S

Sabot

A lightweight carrier in which a sub-calibre projectile is carried: it comes from the French for a clog or shoe. The term, Sabotage, comes from the practice, during the Industrial Revolution, of disenchanted workers throwing their sabots into the new-fangled machines in order to break them.

 

Safety Safety Catch

A mechanical device to reduce the likelihood of accidental discharge of any gun to which it is fitted (provided that it has been engaged at the time): not much used in target shooting circles.

 

Sear

The part of a gun's action that is 'tripped' by the trigger to release the hammer, or firing pin and initiate firing the cartridge.

 

Semi-automatic

A type of action automatically ejects the spent shell and loads another.

 

Semi-wadcutter

A bullet shape halfway between roundnose and wadcutter. Often used in semi-automatic guns to facilitate easy feeding of ammunition from the magazine to the chamber. The shape of the bullet head makes for a neater hole that is easier to score than that of a roundnose.

 

Serpent

The part of the action of a Matchlock gun which carries the match to the pan when the trigger is pulled in order to ignite the priming powder and hence fire the gun.

 

Set Trigger

A very light trigger that is prepared, or set, by the operation of either another lever, or by manipulating the trigger itself.

 

Sectional density

The ratio of the bullet mass to the square of its diameter in inches, so therefore SD=bullet weight in pounds / bullet diameter in inches2.

 

Shot

One of many pieces of lead or steel fired out of a shotgun cartridge, the person using a gun

 

Shot Pattern

The concentration of shot measured in a circle at a given range, usually 30 to 40 yards.

 

Shotshell

The ammunition fired by shotguns, consisting of five components: The case, primer, powder charge, wad, and shot.

 

Side-by-side

Shotgun in which one barrel is alongside the other

 

Sight

Device fitted to a gun to assist the aiming of it in relation to a target. Non optical sights are in two parts, the fore sight mounted at the muzzle end and the rear sight mounted as far to the rear as practical.

 

Sight adjustment

With adjustable rear sights, move the sight adjuster in the direction you wish the shot to go on the target. To move the shot right, move the rear sight to the right etc. Usually sights have right-hand threads on their adjusting screws and this means that clockwise = up on the elevation adjuster and clockwise = right on the lateral (or 'windage') adjuster.

With adjustable front sights, move the sight adjuster in the opposite direction that you wish the shot to go on the target.

 

Sighting picture

The appearance of the sights when they are correctly aligned with each other before the target is in view. See also, aiming picture.

 

Single Action

The type of firearm action whereby one pull of the trigger performs the single function of firing the gun. This term is often used to refer to revolvers, but it applies to all classes of firearm.

 

Skid shot

A shot that hits a turning target whilst it is turning and thus produces an elongated hole. Depending on the length of the 'skid' the shot may be discounted from the total score and thus count as a miss.

 

Smallarm

A military term used to mean any gun designed to be held in the hand when fired.

 

Smallbore

Generally taken to mean .22 rimfire.

 

Smokeless powder

A term usually used to refer to nitro powders. Note that nitro is not totally smoke-free, but compared to Black Powder (gun powder) it is a huge improvement.

 

Smoothbore

A gun which is not rifled and whose barrel is completely 'smooth' all the way from breech to muzzle. The projectile is not spin-stabilised and hence the guns are relatively inaccurate. The most common modern gun that is a smoothbore is a shotgun.

 

Snap Cap

An inert cartridge with a spring loaded primer, used to check gun functioning and for dry fire practice: see Dry Fire above.

 

Spotter

A companion to the shooter on the firing point, who undertakes recording the accuracy of shooting and can advise on wind conditions, especially for long range shooting.

 

Spotting Scope

A telescope on a stand, used to observe the position of a shot on the target from a distance and without having to retrieve it. This is done either by directly viewing the hole, or watching the signals of a marker in the butts (especially at long ranges). Normally a magnification of between 20 and 30 times is used.

 

Stalker

See Deer stalker

 

Sustainable harvest

The amount which can be shot without detriment to the population as a whole

 

Swaging

A process of manufacturing bullets out of lead wire using great pressure to cut and 'swage', or 'squeeze' the bullet into shape. Swaged bullets can be jacketed. This is not usually a practical proposition for home manufacture, due to the large forces and relatively expensive equipment involved.

 

Swiss

Very fine Black Powder, finer than FFFFg and used as a primer in muzzle loading guns.

 

Syndicate

Group of people who shoot together, sharing the costs of a day's or season's sport

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T

Tanning

The art or process of making leather from rawhides.

 

Target

The object, usually made of thin card, at which shooting is directed and which enables scoring of the results.

 

Telescopic Sight

A sight built into a telescope and designed such that the reticule and the target are in focus at the same time. For target shooting purposes the sight must have parallax correction to be of any use.

 

Throat

The unrifled part of the bore immediately in front of the chamber.

 

Throat erosion

The erosion of the throat area caused by the hot gasses of the propellant burning away the metal and limiting the barrel's useful life. This is mainly a problem of high pressure rifle cartridges.

 

Torque reaction

The tendency for the gun when fired to twist in the opposite direction to the rifling. This can be a real problem for pistols when shot single handed, less so for rifles.

 

Trajectory

See bullet path.

 

Trap

1. Mechanical device to capture legal pest and predatory species.

2. A device which throws clay pigeons

 

Trigger

The device normally operated by the shooter's index finger that initiates the firing of a gun.

 

Trigger Shoe

A device which fits over the standard trigger so as to offer a wider surface to the trigger finger and thus give the impression of reducing its apapparent weight.

 

Trigger stop

A device to limit the over-travel of a trigger when pulled: see over-travel above.

 

Trigger Weight

The weight that a trigger must support to comply with competition rules e.g. for air pistol it is 500 grams, for air rifle there is no lower limit as long as the gun is safe to use, or, the weight used to check a competitor's trigger before passing the gun as complying with the rules for shooting.

 

Turning Targets

A device, usually electrically operated (but may be pneumatic) that twists a target through 90o very rapidly so as to present the target to the shooter. Used in timed fire events and controlled by an electronic timer.

 

Twist

The turn of the rifling. For example a barrel with a 12 inch twist means that for every 12 inches of movement down the barrel towards the muzzle, the projectile makes one complete turn (revolution).

 

Two stage trigger

A type of trigger which has (normally) about half the trigger weight to fire the gun taken up by a relatively long rearward movement and the remainder by a crisp sudden let off. This is a device to enable easier shooting, by giving the shooter some idea as to how much weight has been taken up before the shot is fired.

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U

 

No entries for U.

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V

 

Velocity

The speed of a projectile after it has left the barrel normally measured in Feet Per Second.

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W

 

Wad

A disk, or series of disks of soft material used to seal the projectile and powder into the cartridge and or, gun.

 

Wadcutter

A bullet with a flat, circular head the same diameter all the way along its length. Especially used in target shooting as they punch a neat round hole the same diameter as the bullet and thus make scoring easier.

 

Wheel Lock

An early type of muzzle loader lock system which came before the flintlock. A spring driven wheel was released by the trigger. This spinning wheel struck a shower of sparks off a lump of pyrite which led to ignition of the priming charge and hence the main charge. Wheel Lock guns were expensive to make and relatively difficult to keep in good working order; as a consequence many were converted to Flintlock operation.

 

Wildcat

A cartridge designed and made by a handloader by altering an existing cartridge case and usually displaying enhanced velocity over the original donor cartridge.

 

Windage

The lateral sight adjustment so as to move the point of impact sideways on the target, this is usually, but not always done by the rear sight.

 

Wind-doping

The ability to read the changing wind conditions at long range outdoors, so as to be able to compensate for them on a shot-by-shot basis.

 

Wiping-out

A somewhat vague term, used to indicate the removal of oil from a muzzle loading gun before attempting to load it for the first time at a shoot and also the quick clean and squirt of oil down the barrel at the end of a shoot before packing up to leave the range.

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X

 

X-Ring

The name given to a smaller inner ring enclosed within the 10 ring and used as a tie-breaker. Normally the X-Ring does not have a numerical value: see also 'Inner 10' above.